This action was brought to recover the reasonable value of helium intermixed with natural gas, extracted therefrom, and sold by the defendant Phillips to the United States. The plaintiff prevailed against the defendant and the Government as intervenor in the lower court, and they both appeal. Plaintiff also appeals, but only as to the ultimate division of the proceeds derived from the helium as ordered by the trial court.
The case was commenced in the Southern District of Texas, but transferred at defendant’s request to the Northern District of Oklahoma. The complaint asserts jurisdiction based on diversity and this ground was established. The Government intervened as plaintiff, but was realigned as a defendant.
The general description of the occurrence of helium, its characteristics, and how it became an issue is described in the several opinions hereinafter cited. It is, however, necessary to describe the contractual relationship which existed between the defendant Phillips and the Bureau of Mines during the pertinent time period as it bears on the relationship with plaintiff.
The Helium Act (50 U.S.C. § 167 et seq.) was directed to the conservation of helium present in natural gas and which was being wasted by the use of the gas as fuel. It was determined that the best method to prevent this loss was to intercept the flow of helium-bearing natural gas after it had been gathered and where large volumes were being transported by pipeline to the fuel consumers, and to extract the helium therein intermingled. At these points the pipeline companies had possession of the gas stream.
*384The Bureau of Mines pursuant to the Helium Act entered into contracts with those in possession of the natural gas stream to purchase helium after it was extracted from the stream. The record shows that this decision to contract apparently was brought about by the inability of the Bureau to then ascertain the identity of the interest owners in the helium and to deal with them within any reasonable time. The Bureau indicates that there were some 30,-000 landowners involved and several hundred lessee-producers of the gas. The production is from several states and the interest owners reside in many different states. By the contracts with the defendant and others the Bureau made possible the construction of extraction plants and soon came into possession of the helium so removed from the large gas stream. Waste of the helium was so prevented, and the purpose of the Helium Act was accomplished.
We are here concerned with the Government contract with defendant Phillips whereby the helium was physically acquired by the Government, but the ownership and compensation problems were put off to another day. The Bureau thus used by this contract the advantageous position of one in possession; postponed the inevitable legal problems, and placed itself in the position of a defendant when the problems came before a court.
In the contract between the United States as buyer and the defendant as seller covering the purchase of helium, a specific amount was provided as compensation to defendant. The record shows that this figure was arrived at by comparison of the estimated cost to the Government had it built its own plant. No relationship of this figure to any then market values was developed in the record. This was a base price of $10.30 per Mcf and was subject to escalation under Paragraph 7.3. Paragraph 7.4 provided that in addition to such amount the buyer would pay to the seller the amounts “ . . . that Seller shall pay subsequent to the date of this contract . to parties other than itself . for the acquisition of helium in the natural gas ... or for any interest therein.” It provided that such payments to qualify would have to be made with the consent of the buyer, and that “consent” included claims that “ . . . have been judicially determined in favor of any claimants by any Federal Court or the highest appellate court of any state,” and payments made in accordance with the findings, principles, and conclusions of such “judicial determination.” Under the contract formula the defendant would pay the first $3.00 per Mcf to third parties and the Government would pay the rest. The result would be that the ultimate payment to the “owners” was to be so shared by defendant and the United States, with the United States providing an indemnification for required payments above the stated amount. There are other qualifications also.
It is obvious that this litigation wherein compensation is demanded by the interest owners of the helium was contemplated and was provided for in the contract. It was apparent that some knotty legal problems would have to be met in order to determine who the interest owners were, and to decide whether or not they had already been compensated for the helium under the leases, the gas purchase contracts, or the Natural Gas Act. These postponed legal problems were in large part decided in the Consolidated Helium Cases (Northern Natural Gas Co. v. Grounds, 441 F.2d 704 (10th Cir.)), opinion by Judge Breitenstein. The basic legal relationships among the landowners, producers, and gas purchasers were there established, as was the relationship of the Natural Gas Act and the Helium Act. The controlling rules were set in the Grounds opinion, en banc consideration was denied, and the Supreme Court denied certiorari, 404 U.S. 951, 92 S.Ct. 268, 30 L.Ed.2d 267. We decline to reconsider Grounds. Further, in Grounds we held that “ . . . the lessee-producers are entitled to the reasonable value of the contained helium.” The problem of the amount of reasonable compensation, and who should pay, was not decided in Grounds, and was remanded to the trial court. The Grounds case is again *385before this court en banc and was consolidated for hearing with this case, but is not considered in this opinion.
When the matter of compensation is in issue we are faced with a somewhat different aspect of the physical and legal journey helium makes from the natural gas well to the storage facilities of the Bureau of Mines than we have considered before. The possession and interception of the gas stream, the separation of the helium therefrom, and its delivery to the United States under the contract arrangement are all still important, but the relationship of the contracting parties to those who now have been determined to own interests in the helium, and of course, the value of the helium are the center of focus.
The position of the United States as a party herein is somewhat unusual. It filed a motion to intervene as a party plaintiff with a “Complaint in Intervention of the United States” attached. This motion was granted. The complaint of the Government stated that the court had jurisdiction under 28 U.S.C. § 1345, cited 28 U.S.C.A. § 2201, and recited the existence of the contract for the purchase of helium from Phillips, asserted that Phillips had delivered to the United States “large quantities of a helium-gas mixture” for which it had been paid “substantial sums of money.” This complaint acknowledges that the plaintiff Ash-land is seeking “fair market value” of helium in the gas it sold to Phillips which was processed for helium, and the helium in turn sold to the United States under the contract referred to above. The Government further alleges that Ashland has already been paid for the helium content along with the hydrocarbons, and in any event the value of the helium content is “nominal.” The complaint asserts that: “An actual controversy exists between the United States and Ashland as to whether payments between Phillips and Ashland for the gas as produced was payment for the helium content.” The Government also asserts that it “ . . . has a real and substantial interest in this litigation because of a provision in its contract with Phillips under which it may be under a duty to indemnify Phillips for additional payments . ” The Government prayed for a determination that Ashland had already been paid in full, and if not, that the fair market value of the helium was “nominal.” Phillips and Ashland answered the Government’s complaint. Ashland in its answer prayed for costs and general relief.
As the trial opened, the attorney for Phillips suggested that the United States be realigned as a party defendant. The court then said: “The Court will order that the style be changed to Ashland Oil and Refining Company, Plaintiff, versus Phillips Petroleum and United States of America as defendants.” The findings recite that at the Government’s request it was aligned as a defendant and was an intervenor. The United States participated in the trial, cross-examined witnesses, put on a witness of its own, objected to the plaintiff’s findings, and submitted proposed findings. The judgment entered ran against Phillips only. The United States has fully participated in this appeal.
As indicated above, this action was brought by Ashland against the defendant Phillips to recover the reasonable wellhead value of helium commingled with the FPC jurisdictional Gas, but separated at defendant’s plants constructed pursuant to the Helium Act and delivered as “conservation helium” to the Bureau of Mines. The suit was tried within the holding of Northern Natural Gas Co. v. Grounds, 441 F.2d 704 (10th Cir.) (The Consolidated Helium Cases, or Grounds).
On this appeal Phillips devotes much of its brief and argument to contentions which were advanced in Grounds, there considered and rejected. It would serve no purpose to again consider these arguments. Instead it is sufficient to refer to the Grounds opinion for the disposition of these points.
It must be accepted that the “value” sought to be determined in this suit is basically a factual matter determined through the application of the appropriate legal doctrines. This is the value at the wellhead of *386the helium commingled with the natural gas there being produced.
The appellants here urge as a basic error by the trial court that it chose the wrong method in arriving at this “value.” The trial court determined that there was no prevailing market value for the commingled helium, there was no free competitive market for this helium at the wellhead. The court thus used a market value for the ultimate product less the cost of beneficiation of the helium-bearing gas. The defendants urge that the trial court had sufficient evidence before it of a “market value” of the commingled helium at the wellhead.
The defendants, on their “market value” theory, put on testimony and exhibits as to transactions concerning helium-bearing gas wherein a value was ascribed to the helium component. These described events covered a broad time span and a wide geographical distribution. They involved both governmental agencies and private parties.
The trial court, in holding that there was no free competitive market, held that these transactions were of no probative value because they were not comparable. It thus concluded that the evidence failed to establish a “market price” by comparable sales. We reach the same conclusion. The transactions described by the witnesses for the defendant were too remote in time or place, and otherwise could not be considered as comparable. The testimony did not show a free market condition to establish a usable price. It is apparent that the gas stream here concerned with all its components was directed by the FPC, and was locked in by the jurisdictional gas. There was not an opportunity for free pricing at any point, nor for renegotiation of sales or the negotiation with new purchases. The helium thus had to go along with the stream. The purchasers of the stream here concerned, of course, took the position that they owned the entire contents, and were not required to pay anything more. This litigation demonstrates the character of the market, the Government domination of the market, and the strength of bare possession.
In the market price evidence of the defendant, considerable detail is presented as to purchases at the several Government helium plants. These include the plants at Exell, Otis, Cunningham, and Navajo. The helium purchases or gas purchases at these plants were made during World War II. The years which have passed since “The War” would seem to cast more than a doubt that these could possibly be comparable sales. The purchases at the. Navajo plant were renegotiated after the War in 1955 and 1959, but again this cannot be a comparable transaction. The stream from the Rattlesnake production had no use as a fuel. It did have a high helium content, but nothing is developed as to any other market for this gas. The Government had for all practical purposes a monopoly on sales of helium until about 1962.
There was also testimony as to purchases of gas by the Government for the Keyes plant in 1958. The price was somewhere near $2.00 per Mcf. The production costs at this plant were about $15.50 per Mcf. The basic interest of the seller was to make the residue gas marketable by raising the BTU. The seller also assumed liability for possible additional payments to third parties.
The Otis plant was also used to upgrade the gas for fuel purposes by separating out the noncombustible portions of the stream.
Phillips also introduced evidence as to several contracts it had made for the payment for components of the gas production purchased. Some mentioned helium, some did not. This was a dollar price in some, and a formula as for all other components in others. These are not of particular significance, especially the casinghead gas contracts, because there was no evidence that the casinghead gas contained helium nor was ever processed for helium. As to the other Phillips contracts, there was no showing that the gas had a helium content at all (with insignificant exceptions), nor that there was ever a remote possibility of extraction, again with insignificant exceptions. Contractual provisions in such a context, even where helium was mentioned, are a meaningless gesture of the parties, and *387cannot be considered as evidence of comparable sales.
The Gas Sales Agreement between Colorado Interstate and Alamo Chemical Company (a Phillips affiliate or subsidiary) was put in evidence. This provided for the processing of gas produced in Morton County, Kansas, for the removal of helium and liquefiable hydrocarbons. The plant operator was to pay $2.00 per Mef for helium extracted at the plant. This price was not negotiated, and it seems reasonable to assume that this was because there was litigation pending as to the obligations to pay for helium involving the parties. The contract limited the sellers’ liability on the title warranty of helium to $2.00 per Mcf. There was no contract provision for payment for hydrocarbons removed. This contract must be considered for all practical purposes as a post-litigation contract. There was also in evidence a gas exchange agreement between Phillips and Pioneer Natural Gas Company. This had a price for helium but there were other contractual considerations such as delivery of gas at other locations, and payment for only part of the helium. This agreement cannot be considered as a comparable sale.
The testimony of the defendants and evidence was thus directed to “other sales” in other places and other times. There was no substantial showing that these were “comparable sales.” Evidence of “other sales” falls far short of establishing a market without comparability being clearly established.
In addition to the evidence relating to particular contract provisions, and some sales, there was expert testimony. The plaintiffs and defendants had expert witnesses who testified as to what the value of helium should be. This testimony produced by both sides is of theoretical interest, presents a facet of the entire conservation program, and a description of the few independent private enterprises which tried to enter the field. No matter how interesting, this evidence is only opinion evidence, and does not establish facts. This testimony comes well down on the scale of acceptable evidence as to value. It is obvious that comparable sales or current market price is the best, and second would come the work-back method. The expert testimony of the type here presented would come somewhere after that. The experts were extremely capable, experienced persons who gave well considered and conscientious expression of their opinions, but nevertheless it remained opinion evidence on a matter of objective facts.
We thus must agree that the trial court was correct in seeking an alternative method to “market price” for establishing the reasonable value of the helium component at the wellhead. It is obvious that the comparable sales-current market price is by far the preferable method when it can be used. However, it cannot be used when the elements necessary for its proper application are lacking. The trial court thus had to resort to a work-back method or price less costs of beneficiation. This was a less desirable method but perfectly valid. Under this method a point was selected where there can be determined an established price and the costs of processing or beneficiation were deducted to move back to the place where the value must be established.
The work-back valuation is well recognized in the production and early processing of natural gas. It is commonly used, according to this record, in placing a value on feed stock for gasoline plants and related processing. There is nothing unusual about the method, it is subject to proof, and can be just as accurate as any other method, but it is more difficult to apply. There is here concerned a single plant constructed and operated for the specific purpose of extracting helium. Other costs, and other elements, can be established. This work-back method was used by the Government and the Court of Claims in making payment to the Navajos for gas supplied to the Navajo Helium Plant. See Navajo Tribe v. United States, 364 F.2d 320, 176 Ct.Cl. 502. The Government has used it on other occasions such as for Kerr-McGee royalty payment in Arizona, and under different circumstances. As to the work-back as a *388method for valuation see also Brown, Law of Oil and Gas Leases, § 6.09; Harding v. Cameron, 220 F.Supp. 466 (W.D.Okl.); and Sneed, 25 Tax L.Rev. 641. This method to establish value has not only been used in the petroleum industry, but also in other natural resources cases. See United States v. Wyoming, 331 U.S. 440, 67 S.Ct. 1319, 91 L.Ed. 1590; Black Crystal Coal Co. v. Garland Coal & Mining Co., 267 F.2d 569 (10th Cir.); and Greer v. Stanolind Oil & Gas Co., 200 F.2d 920 (10th Cir.). See also the gasoline plant case, Freeland v. Sun Oil Co., 277 F.2d 154 (5th Cir.), which is a common use in the industry.
Phillips argues that its right to acquire the helium component was covered by its contracts, and neither the Helium Act nor the Natural Gas Act altered these contracts. Thus there was a Fifth Amendment violation if its property was “given” to another. This court on the Grounds case really decided this issue and there would seem to be no need to consider it again other than to state that Phillips acquired the whole stream or production, but has only paid for part. We said in Grounds, “In our opinion private contract law and the principles applicable thereto are not controlling.” Apparently the Government has yet to pay Phillips for much of it also.
The appellant next argues that the value less expense method was not only inapplicable, but it was improperly applied in that the proof was deficient as to certain elements, that mistakes were made, and that “trifling recognition” was given to certain evidence. We will take these references to mean that there was not substantial evidence on the several factors or elements of the method of valuation.
As to the several elements, the appellants urge that the amount used as the “return on investment” expense was not sufficient. The trial court used a figure which was part of the testimony of plaintiff’s witnesses, and the method by which it was arrived at was so presented. There was no substantial contrary evidence presented at trial although on appeal appellants assert deficiencies in the method. This element however was not adequately developed by the proof and further hearing is required on this element.
The appellants also object to the allowance made by the trial court of $2.00 per Mcf for the “treatment” of the “crude” helium sold to it by Phillips (to be incurred by the Government before resale), as insufficient in that it did not include transportation and storage. Matters of expense to be incurred subsequent to the delivery and perhaps some transportation from place of delivery to the underground storage are not shown to have been omitted from the $2.00 figure although it was denominated a “treatment” or “processing” cost. In any event, these costs are more properly attributable to the general conservation program as the duration of the storage and additional transportation are unknown factors under the record. The use of the deduction was proper and appellants have not shown that it was not supported by substantial evidence.
The trial court used a figure of $20.00 per Mcf for the selling price of helium, and this was the starting figure or element of the value less expense method. This figure was testified to by the witness for the plaintiffs; this price issue was not met by defendant by way of proof. On remand the validity of this figure must be examined by the trial court, and a determination made again as to. the proper starting value.
The Government, in an argument' again based on condemnation doctrine, urges that the helium values were created by its own purchase program — The Helium Conservation Program, and it should not, have to pay for such values. It cites several condemnation cases on this point, and United States v. Fuller, 409 U.S. 488, 93 S.Ct. 801, 35 L.Ed.2d 16, which in turn cited United States v. Cors, 337 U.S. 325, 69 S.Ct. 1086, 93 L.Ed. 1392. This again concerned payment for something requisitioned by the Government. The issue here is the determination of value of a commodity which was purchased and sold by the Government and by private concerns. It was a stockpiling of a commercial product. This cannot be *389equated to the cases where the condemnation or the reason for condemnation increases the value of the land taken. The helium has value by reason of its nature and usefulness. The Government may have made this helium available but did not create its value.
The appellants vigorously attack the use by the trial court of the value of hydrocarbon liquids produced at the helium plants in the value less expense calculations. The trial court allocated part of the plant expense to these liquids as by-products. The evidence is unclear that an increase in the production of liquids would result from the helium plant operation over what had been experienced before and over ordinary extraction plants. Appellants maintained that the increase in liquid production did not result at all from the treatment of the gas stream for helium, extractions. The record shows that increased quantities of wet gas were directed to at least one of the plants, and this could make a difference in the production of liquids, but no figures were produced by defendants. Under this state of the record, we must hold that the trial court did not have adequate data to this element. Different quantities of liquids were produced at different plants, and this may result in different helium values at different plants. In view of the evidence, this was a consequence of the application of the expense element in the formula. However, further evidence on this aspect is needed.
The Government makes the point that the value of helium at the wellhead determined by the trial court exceeds the base figure for the helium-nitrogen mixture it was buying from Phillips under its contract. This may be a consequence of the decision, but there is no reason why the wellhead price should be determined by the contract price. This payment was not necessarily the “price” of the helium as other considerations were present. The contract between the appellants was negotiated between them alone, and the pricing was the evaluation by them of the entire economic consequences of the transaction including many significant factors such as its duration, warranties, and indemnities. We have described the contract at the outset of this opinion. Attention should however be directed again to the evaluations made of the legal questions, especially the title questions. The Government agreed basically to pay Phillips for its interest in the helium and then to pay more if other interest owners established their claims. This has been done, but the price “paid” for all the interests in the helium has not yet been determined. The value here sought to be established is independent of the contract base amount, and is to be of all interests of the proper parties.
We have considered Lippert v. Angle, 211 Kan. 695, 508 P.2d 920. It states the traditional preference for comparable sales proof with which we agree, but the case does not involve the separate valuation of helium. The plant was very small, and the situation is not comparable in any way. See also Greenshields v. Warren Petroleum Corp., 248 F.2d 61 (10th Cir.).
This appeal also raises issues as to the allowance of prejudgment interest, attorney fees, and the matter of limitations. The trial court tried the case as a federal question case, relying on our opinion in Texaco Inc. v. Phillips Petroleum Co., 481 F.2d 70 (10th Cir.), which was thereafter reversed by the Supreme Court in Phillips Petroleum Co. v. Texaco Inc., 415 U.S. 125, 94 S.Ct. 1002, 39 L.Ed.2d 209. That case was concerned only with federal question jurisdiction under 28 U.S.C. § 1331(a), and not whether state or federal law controls. The United States was not there a party. Federal jurisdiction is here conceded.
The original Consolidated Helium Cases were based on federal interpleader jurisdiction, and also federal law was applied. The case before us on this appeal started as a diversity suit, and the Government has asserted a claim or an interest. We have described at some length above the participation of the United States in this action, especially the initial intervention as a plaintiff expressly under 28 U.S.C. § 1345. It is apparent however that its alignment at all *390times was with the defendant Phillips on all important issues. No relief was sought by Ashland directly against the United States. The trial court found the elements of a condemnation or seizure by the United States, but this analysis of the manner in which helium was acquired was considered in the Consolidated Helium Cases, and the arguments were rejected.
As a matter apart from jurisdiction, we hold that the trial court’s application of federal law was proper. The action of the Government in entering the case as a plaintiff under 28 U.S.C. § 1345 is a significant factor to be considered. The real party in interest thus appeared formally to challenge the claims of Ashland. The Government so asserted that it had a real and substantial interest in the litigation, and that an actual controversy existed between it and Ashland. It is apparent that under the contractual arrangement, the United States undertook to pay to Phillips the amounts that Phillips “shall pay” to other parties for the acquisition of helium in the natural gas above a certain figure. This is in the nature of an indemnity agreement and the contract contains qualifications and limitations not here concerned. The United States is liable for some of the additional amounts which Phillips will have to pay. The Government has thus entered the litigation to assert its own position and interest under the contract. This is initially a matter of dollars, but the Government still has possession of a large part of the helium in question, and this possession can put a somewhat different cast on the problem. These circumstances and the intervention could very well have changed the action to something other than the usual diversity suit at least for the purpose of the application of Erie v. Tompkins. This has interesting possibilities, but in any event, the circumstances direct that federal law be applied.
As indicated above, and as demonstrated in Northern Natural Gas Co. v. Grounds, 441 F.2d 704 (10th Cir.), and by the record here, the Government in the several cases before this court is faced with claims made by a multitude of interest owners from many states relating to production from Kansas, Oklahoma, and Texas. Each state has somewhat different legal doctrines relating, among other things, to the nature of interests in oil and gas, and what rights are created by oil and gas leases. With the primary liability for the dollars, and for the determination of ownership resting with the United States which obtained possession of the helium, we hold that the application of the rule expressed in Clearfield Trust Co. v. United States, 318 U.S. 363, 63 S.Ct. 573, 87 L.Ed. 838, is indicated. One of the most significant factors is the one indicated above, that is, the fact that the United States ended up with the helium. It directed, by contracting, the diversion of the helium to itself before resolving the obvious ownership problems with a multitude of claimants having diverse legal relationships to the helium, depending upon the place where the natural gas was produced and upon their contractual positions. The United States, again by contract, sought to handle these problems by providing for reimbursement to Phillips, and it may have done so. The Government nevertheless obviously has the basic responsibility and liability, as it recognizes by its intervention.
Erie v. Tompkins does not demand the application of state law to all diversity actions. The Court in the Clearfield Trust case set out an exception which was there applied to “obligations” of the United States and later expanded. The case concerned the forgery of a Government check, and a delay in notice by the Government to the bank beyond the period contemplated under state law. The Court held that rights of the Government relating to commercial paper it issues are determined by federal and not state law. The Court said that the authority to issue the check in question originated in the Constitution and statutes of the United States and was not dependent on the laws of any state. In the matter before us, the helium was acquired by the United States by contracts as authorized by federal statutes. This contracting with private enterprise was suggested by statute. As stated by the Court in the cited *391case, “The desirability of a uniform rule is plain.” See also National Metropolitan Bank v. United States, 323 U.S. 454, 65 S.Ct. 354, 19 L.Ed. 383, limited by Bank of America v. Parnell, 352 U.S. 29, 77 S.Ct. 119, 1 L.Ed.2d 93. The War Bond cases in state and federal courts lead to the same result. See In re Stanley’s Estate, 102 Colo. 422, 80 P.2d 332. The Court in D’Oench, Duhme & Co. v. FDIC, 315 U.S. 447, 62 S.Ct. 676, 86 L.Ed. 956, also indicated a considerable area to be excluded from the application of Erie. There an action by the FDIC was brought on a note given to a bank by the defendant, and the Court applied federal law. Also in the shareholders’ liability action in Holmberg v. Armbrecht, 327 U.S. 392, 66 S.Ct. 582, 90 L.Ed. 743, in the solution of a limitations problem, the federal law was applied. Generally, see 59 Harv.L.Rev. 976, and 105 U.Pa.L.Rev. 797.
Under Clearfield when the United States seeks to litigate or seek a remedy arising from transactions it has entered into in the ordinary commercial world to carry out its program, it has been held that federal law may be applied. The federal courts can adopt a governing rule of law in such circumstances if there is no statutory direction to the contrary. Clearfield expressly so held. 318 U.S. at 366, 63 S.Ct. 573. See also United States v. Allegheny County, 322 U.S. 174, 64 S.Ct. 908, 88 L.Ed. 1209. Clearfield thus indicates that the Court may apply state doctrines or parts of them as “federal law.” In United States v. Standard Oil Co., 332 U.S. 301, 67 S.Ct. 1604, 91 L.Ed. 2067, the Court stated that the interests of the Government and its legal relationships may be so determined. The impact of the application of state law upon the governmental interests is a factor of great weight. See United States v. Mitchell, 403 U.S. 190, 91 S.Ct. 1763, 29 L.Ed.2d 406.
The Court in United States v. Little Lake Misere Land Co., 412 U.S. 580, 93 S.Ct. 2389, 37 L.Ed.2d 187, considered the application of a Louisiana statute to the reservation of a mineral interest in land acquired by the United States. The factors discussed above were there treated, and the process was described as a “choice' of law” (federal or state) matter. The Court there said:
“However, in a setting in which the rights of the United States are at issue in a contract to which it is a party and ‘the issue’s outcome bears some relationship to a federal program, no rule may be applied which would not be wholly in accord with that purpose.’ ” [The quotation included being from Mishkin, 105 U.Pa.L. Rev. at pp. 805-6.]
The Court found further that the federal land acquisition program in United States v. Little Lake Misere Land Co. conflicted with the state law on the duration of reserved mineral interests, and said: “The choice of law merges with the constitutional demands of controlling federal legislation; we turn away from state law by default.”
In the case before us, the United States was seeking to carry out the Helium Conservation Program then considered of great urgency and importance. It sought to, and did, acquire possession of the helium as directed by the legislation. The action of the Bureau of Mines was efficient and effective. In so doing it set up the contractual barriers between itself and the landowners and gas producers, and also put off the inevitable day of reckoning as to ownership. Phillips is really only a nominal party and looking at the substance, the Government has the responsibility arising from its acquisition and possession of the helium. In the face of the multitude of claimants, the variations in state law, and the Clearfield doctrine, the trial court was correct in not applying Erie v. Tompkins.
We find no merit to the contention of Phillips that it is entitled to a setoff for any sums previously paid to Ashland for purchases of jurisdictional gas.
The court in the Consolidated Helium Cases considered the ownership of the interests, title to the helium, and described how these passed down the gas stream. This determination prevails. The trial court, as to the interest of the landowners-lessors, apparently followed a confiscation-*392condemnation theory and divided the value of the helium to be recovered from defendant Phillips equally between the lessors and lessees. Our opinion in the Consolidated Helium Cases requires that this division be in accordance with the lease terms, and thus the same division as applied to the hydrocarbons. The judgment of the trial court making an equal division between lessor and lessee of the proceeds attributable to helium values must be and is reversed with directions to enter judgment providing for a division in accordance with the terms of the leases, and the terms of other agreements relating to the shares of production, or payment for shares of production, if such be applicable.
The issue of limitations has been raised together with the tolling of whatever statute may be applicable. This litigation concerning the property interests in helium and the right to compensation, considering the related cases, has been protracted and equitable considerations applicable to periods of limitations have come into play. See deHaas v. Empire Petroleum Co., 435 F.2d 1223 (10th Cir.). We must conclude that this action has not been barred. American Pipe & Construction Co. v. Utah, 414 U.S. 538, 94 S.Ct. 756, 38 L.Ed.2d 713.
The trial court acted within its discretion under federal law in the allowance of prejudgment interest. Royal Indemnity Co. v. United States, 313 U.S. 289, 61 S.Ct. 995, 85 L.Ed. 1361; St. Paul Mercury Indemnity Co. v. United States, 201 F.2d 57 (10th Cir.).
As to attorney fees awarded by the trial court, we are unable to find any statutory provision for them or any rule of practice which would authorize such fees. The Supreme Court has, since the trial court’s decision, decided F. D. Rich Co. v. Industrial Lumber Co., 417 U.S. 116, 94 S.Ct. 2157, 40 L.Ed.2d 703, a Miller Act case. The opinion includes a direct and intensive consideration of attorney fees. The Court there defines the basic rule:
“The so-called ‘American Rule’ governing the award of attorneys’ fees in litigation in the federal courts is that attorneys’ fees ‘are not ordinarily recoverable in the absence of a statute or enforceable contract providing therefor.’ ”
The Court concluded that Miller Act suits are “plain and simple commercial litigation,” and the Court would not change the American Rule “in the context of everyday commercial litigation.” We must hold that this litigation is not so dissimilar to Miller Act suits as to bring about a different result as to attorney fees than expressed in F. D. Rich Co. See also Alyeska Pipeline Co. v. Wilderness Society, 421 U.S. 240, 95 S.Ct. 1612, 44 L.Ed.2d 141.
The judgment of the trial court is thus REVERSED as to the award of attorney fees, and as to the equal division between lessor and lessee of the proceeds attributed to the value of the helium, as above indicated. The judgment is also set aside as to the valuation determination with direction to hear further the matters or elements of the work-back method, referred to above, wherein there was insufficient evidence in the record.
Thus some elements have been considered in this opinion and ruled on.
On remand the trial court shall also consider whatever other elements that may be developed at further hearing, in making the value less expense or work-back determination.
Thus, we affirm the use of the work-back method of determining value and the use therein of the $2.00 figure for treatment of crude helium. We set aside the values which the trial court determined by the use of the work-back method. On remand the trial court shall give further consideration to, and receive such evidence as may be admissible bearing on, (1) the proper starting value, (2) the amount chargeable to return on investment, (3) the expense properly allocable to production of hydrocarbons, and (4) such other matters, as are pertinent and not foreclosed herein, that bear on the determination of value by the work-back method.
We affirm the decision of the trial court that the action is not barred by any statute *393of limitation and that prejudgment interest may be allowed. We reversed those portions of the judgment that (1) allow attorneys’ fees and (2) divide the recovery equally between the lessors and the lessees. The lessors may recover only the amounts determined by the royalty provisions of their leases.
AFFIRMED IN PART, REVERSED IN PART, and remanded for further proceedings in the light of this opinion. Each party shall bear its own costs.