The primary questions which must be resolved in this appeal are whether an employee of the State of Wyoming is immune from suit by virtue of the provisions of the Wyoming Governmental Claims Act, §§ 1— 39-101, et seq., W.S.1977, and whether the State of Wyoming can claim a bar to this suit by virtue of a settlement of a claim against a different State employee, also pursuant to the provisions of the Wyoming Governmental Claims Act. Further issues are asserted relating to error by the district court in excluding additional witnesses and exhibits proffered by the defendants; the failure of the plaintiffs to establish that the actions of the defendant Kinniburgh were a proximate cause of the accident; and error with respect to a refusal to instruct the jury concerning the duty of an adjacent landowner. Finally the appellants assert error in the award of costs to the plaintiffs. We affirm the judgment entered by the trial court except for the amount of costs awarded, which we will require to be modified.
The appellant, G. M. Kinniburgh, a patrolman for the Wyoming Highway Patrol, asserts as the primary issue relating to him that the trial court erred in denying his motion for summary judgment because he is immune from suit pursuant to the provisions of the Wyoming Governmental Claims Act. The appellant, the State of Wyoming, further contends that it had achieved a compromise and settlement of any claims against it; the actions of the appellees, Susan Dieringer, Bonnie Roberts and Connie Mark, therefore were barred as to the State of Wyoming; and the trial court erred in not granting the State’s motion for summary judgment. Both appellants claim error on the part of the district court in excluding the testimony of certain witnesses and certain exhibits on the ground that they had failed to give proper and timely notice of such additional witnesses and exhibits to the appellees prior to trial in accordance with the court’s pretrial order. Both appellants assert as a further issue that this judgment must be reversed because the evidence did not establish that the conduct of patrolman Kinniburgh was a proximate cause of the injuries to the ap-*5pellees, and the district court erred in refusing to grant their motion for a directed verdict, which in part was premised upon this insufficiency in the evidence. As a further issue the appellants assert that the district court erred in refusing to give to the jury their offered instruction relating to the duty and responsibility of Clark’s Ready Mix, the owner of premises adjacent to the highway, which had been named as a party when the action was filed. The final issue asserted by both appellants is error on the part of the district court in awarding costs to the appellees.
On a mild day in February 1981, water was running across Highway 22 near the twon of Jackson from property adjacent to the highway owned by Clark’s Ready Mix. The source of this water apparently was melting snow. As the temperatures cooled in the evening of that day a patch of black ice began to form on the highway from water tracked along the highway by passing vehicles. As night began to fall and the temperatures dropped more the patch of ice became larger and larger. It was primarily forming in the right lane of the highway as travelers were leaving the town of Jackson, at a point just beyond the crest of a hill at the beginning of a curve where vehicles normally would accelerate.
Around 7:30 p.m. a vehicle went out of control and off the road into the borrow pit when it encountered the ice. Patrolman Kinniburgh was called to the scene of that accident by a deputy of the Teton County Sheriff’s Office. Marks at the scene of that accident indicated that other vehicles also had skidded off the road at that site, but apparently they were able to get back on the road without reporting any difficulty. At that time the deputy sheriff suggested that Patrolman Kinniburgh should call the Wyoming Highway Department to have the area sanded. Kinniburgh decided not to do that, articulating his decision in offensive language which undoubtedly had some impact upon the jury. He did not report the condition of the road or request that it be sanded.
About four hours later, at approximately 11:30 p.m., the three appellees were riding as passengers in a vehicle which skidded on this patch of ice, went out of control, crossed over into the other lane of traffic, and was struck by an oncoming truck. All three appellees suffered severe injuries in that accident. They brought suit, seeking recovery from Patrolman Kinniburgh, Jack Oakley, the Wyoming State Highway Department, the State of Wyoming, Clark’s Ready Mix and Construction, and Lynn Clark and Lewell Clark. The Wyoming State Highway Department and the State of Wyoming were named as co-defendants in the separate counts of the complaint seeking recovery from Patrolman Kinni-burgh and Jack Oakley, both of whom were employees of the State of Wyoming.
At the time Jack Oakley was employed by the Wyoming State Highway Department as the local maintenance foreman for the Wyoming State Highway Department. He was authorized to decide whether or not to sand the highway at any particular location, and he was not subject to the direction or control of Patrolman Kinniburgh. Lynn Clark and Lewell Clark owned the corporate stock of Clark’s Ready Mix, and as indicated the water flowing across the highway came from premises owned by Clark’s Ready Mix. Prior to trial, Lynn Clark, Lewell Clark, and Clark’s Ready Mix stipulated with the appellees that the appel-lees’ complaint against these parties would be dismissed with prejudice. Also prior to trial the State of Wyoming, Wyoming State Highway Department, and Jack Oakley moved for an order dismissing claims of the appellees against them because of a compromise and settlement of those claims. The order granting this motion was entered after the trial. The ease actually went to trial then with only Patrolman Kinniburgh and the State of Wyoming as defendants. From judgments entered in favor of the several appellees appropriate appeals were taken which are consolidated in this ease.
We will first address Kinniburgh’s claim that he is immune from suit. He relies upon § 1-39-104, W.S.1977 (1985 *6Cum.Supp.), which provides in pertinent part as follows:
“(a) A governmental entity and its public employees while acting within the scope of duties are granted immunity from liability for any tort except as provided by W.S. 1-39-105 through 1-39-112. * *”
Kinniburgh concedes that § 1-39-112, W.S. 1977 (1985 Cum.Supp.), provides:
“A governmental entity is liable for damages resulting from tortious conduct of law enforcement officers while acting within the scope of their duties.”
It is his contention, however, that immunity is granted pursuant to § 1-39-104, W.S. 1977 (1985 Cum.Supp.), and that § 1-39-112 creates an exception extending only to the governmental entity and not to the public employee. According to his theory it follows that there is no exception as to the public employee, and he enjoys immunity-
We dealt with a substantially identical claim in denying the petition for rehearing in Hamlin v. Transcon Lines, Wyo., 697 P.2d 606 (1985), reh. denied, 701 P.2d 1139 (1985). We there held that a public employee is not immune from suit based upon our analysis of the entire Wyoming Governmental Claims Act.
To what we said in Hamlin v. Transcon Lines, supra, we add the proposition that, given the state of the law in Wyoming at the time of the adoption of the Wyoming Governmental Claims Act, an employee of the State enjoyed immunity that can best be described as derivative from the immunity of the State. Against that legal history we can understand that in drafting the exceptions to immunity of the State and public employees the legislature must have assumed that when immunity of the State was withdrawn by virtue of an exception such as that contained in § 1-39-112 there remained no immunity for a public employee because that individual’s immunity was purely dependent upon the immunity of the State. Read in this light the exceptions to immunity include both the State and the public employee involved, and the grant of the immunity in § 1-39-104, upon which Kinniburgh relies, must be perceived as limited to those situations not encompassed by the exceptions.
We note that Oyler v. State, Wyo., 618 P.2d 1042 (1980), which questioned the common-law immunity of public employees, had not been decided at the time of the adoption of the Wyoming Governmental Claims Act. The pertinent decisions at the time of the adoption of the act were Osborn v. Lawson, Wyo., 374 P.2d 201 (1962); and Price v. State Highway Commission, 62 Wyo. 385, 167 P.2d 309 (1946). The opinion in Price is somewhat equivocal because there was no need for this court to consider contributory negligence on the part of Price if Daly, the driver of the snowplow, was immune from liability. That proposition was substantially clarified in Osborn v. Lawson, supra, but it is there that the immunity of the employee is more clearly made dependent upon the immunity of the employer, the State of Wyoming.
In the light of what we said in Hamlin v. Transcon Lines, supra, together with the historical articulation of public employee immunity, it is clear that in adopting the Wyoming Governmental Claims Act the legislature did not intend to immunize the public employee from suit. His protection is found in the duty of the State to provide him a defense and to save him harmless and indemnify him against any claim or judgment arising out of an act or omission occurring within the scope of his duties in accordance with § l-39-104(b), W.S.1977 (1985 Cum.Supp.). There was no error in refusing to grant Kinniburgh’s motion for summary judgment.
The motion for summary judgment on behalf of the State of Wyoming specifically invokes the provisions of § 1-39-116(b), W.S.1977 (1985 Cum.Supp.), which provides:
“(b) The judgment in an action or a settlement under this act constitutes a complete bar to any action by the claimant, by reason of the same transaction or occurrence which was the subject matter *7of the original suit or claim, against the governmental entity or the public employee whose negligence gave rise to the claim.”
The State of Wyoming then asserts the effect of its settlement of the counts of the complaint relating to the State of Wyoming, Wyoming State Highway Department, and Jack Oakley is to bar this action. The Motion to Dismiss, which was granted by the court in favor of the State of Wyoming, Wyoming State Highway Department, and Jack Oakley, stated, after reporting the basis of the settlement with the several appellees:
“ * ⅜ ⅜ However, it is not the intention of Plaintiffs and said Defendants for the Court to dismiss claims against the State of Wyoming, Wyoming State Highway Department and G.M. Kinniburgh as alleged in Counts III and IV of Plaintiffs’ Complaint and said claims have not been settled.”
In the “Release and Covenant Not to Sue or Execute” attached to the Motion to Dismiss the following language is found:
“This agreement, however, is not intended by the parties hereto to release any claim against the State of Wyoming, Wyoming State Highway Department and G.M. Kinniburgh for injuries and damages sustained by Plaintiffs as a result of the intentional or negligent acts or omissions of G.M. Kinniburgh or other agents or employees of the Wyoming Highway Patrol, as alleged in Counts III and IV of Plaintiffs’ Complaint. * * * ”
We can say without fear of contradiction that separate insurance carriers were defending the claims asserted against Jack Oakley and Patrolman Kinniburgh. The State of Wyoming then accepted the Release and Covenant Not to Sue or Execute as limited by the language quoted above, and confirmed that limitation in its Motion to Dismiss presented to the district court. That limitation was recognized in the order entered which limited dismissal to those claims “as alleged in Counts II and IV.” In a case not involving the State of Wyoming this court has upheld the reservation of a right to sue contained in a covenant not to execute. Lopez. v. Arryo, Wyo., 489 P.2d 626 (1971).
Without addressing the unconscionability of the position of the State of Wyoming in this instance, we hold that the issue of the State’s claim that this action became barred by virtue of the Oakley settlement is resolved in the statute. Section 1-39-115, W.S.1977 (1985 Cum.Supp.), provides that when a claim is received the Insurance Claims Division of the Department of Administration and Fiscal Control shall send the claim to the insurance company insuring the risk involved for investigation and adjustment. In this instance two referrals were made, and that action by the State effectively identified separate claims. We are satisfied that the legislature intended the same connotation of the word “claim” in § 1-39-116, W.S.1977 (1985 Cum.Supp.), as it intended for that word in § 1-39-115, W.S.1977 (1985 Cum.Supp.). The settlement of the claim against Oakley was not a settlement by reason of the same transaction or occurrence which was the subject matter of the original claim against Kinni-burgh. Those two claims had been identified as separate and different by the State of Wyoming. Consequently the settlement of the claim against Oakley does not bar the assertion of the claim against Kinni-burgh pursuant to § l-39-116(b), W.S.1977 (1985 Cum.Supp.). The district court did not err in denying the Motion for Summary Judgment by the State of Wyoming.
Both Kinniburgh and the State of Wyoming complain of error in excluding additional witnesses whom the appellants wished to call and additional exhibits which they wished to offer on the ground that they had failed to comply with the pretrial order. The pretrial order provided in this regard:
“WITNESSES. All witnesses have been named. The parties will notify each other in writing not later than July 15, 1983 of any additional witnesses by name and address, along with a detailed statement of the testimony of each. That is not a summary, that is a detailed statement. *8“EXHIBITS. The parties have listed their exhibits. All exhibits will be marked before trial. Plaintiffs’ with numbers in sequence and defendants’ with appropriate letters in sequence. Each party will notify the other not later than July 15, 1983 of any other exhibits intended for use in the case and furnish copies of the same, or if not feasible, to make the same available for inspection. Unless written objection is filed and served not later than July 22, 1983, all exhibits which have been noticed will be admissible without further foundation.” (Emphasis in original.)
The appellants claim that they complied with this requirement of the pretrial order by placing their notice of additional witnesses and exhibits in the mail addressed to the appellees on July 15, 1983.
When the district judge first advised the appellants of his intention to exclude the additional witnesses and exhibits, he stated that “notification for the Court is that you notify somebody by a date of a particular happening, not mailing. Mailing is not notification in this instance.” At the trial the appellants made an offer of proof concerning the additional witnesses. The district judge then denied the offer of proof on three grounds: First, the offer itself was not in proper form; second, the appellants had failed to give notification to opposing counsel by July 15; and third, the appellants had failed to give a “detailed statement of the testimony as opposed to a summary.”
The trial court in Wyoming has discretion in determining the requirements of adherence to pretrial and discovery orders. Caterpillar Tractor Co. v. Donahue, Wyo., 674 P.2d 1276 (1983); Caldwell v. Yamaha Motor Co., Ltd., Wyo., 648 P.2d 519 (1982), quoting Ford Motor Co. v. Kuhbacher, Wyo., 518 P.2d 1255 (1974). Furthermore, it is our rule of jurisprudence that this court will uphold the action of the trial court if any reason appears in the record which supports the trial court’s determination. ABC Builders v. Phillips, Wyo., 632 P.2d 925 (1981). In this instance the trial court was justified in determining that the required detailed statement of testimony of the witnesses was not provided. Even in briefs and arguments to this court the appellants have not specified the significance of the testimony of these additional witnesses by explaining clearly what the purpose and necessity of that testimony would have been in the case. We are justified in deeming the claim of error with respect to the additional exhibits waived because no offer of such exhibits was made at the trial. Consequently we cannot reach any conclusion with respect to prejudice.
In their next claim of error the appellants insist that the plaintiffs failed to establish by sufficient evidence that any action of Patrolman Kinniburgh was a proximate cause of the accident. Unless reasonable people could not disagree on the question, proximate cause is a question to be resolved by the trier of fact. Buckley v. Bell, Wyo., 703 P.2d 1089 (1985), and authorities therein cited. Since causation is a question of fact to be resolved by the trier of fact, this issue essentially challenges the sufficiency of the evidence to support the finding of the jury. In resolving that contention we must accept as true the evidence of the successful party, giving it every favorable inference which reasonably can be drawn, and we leave out of consideration contrary evidence by the unsuccessful party. E.g., Pine Creek Canal No. 1 v. Stadler, Wyo., 685 P.2d 13 (1984); Anderson v. Bauer, Wyo., 681 P.2d 1316 (1984); Landmark, Inc. v. Stockmen’s Bank & Trust Co., Wyo., 680 P.2d 471 (1984); Grosskopf v. Grosskopf, Wyo., 677 P.2d 814 (1984). Specifically this record reveals that when the first reported accident occurred the patch of ice was about one hundred to two hundred feet long just after 7 p.m. It was black ice and extremely slick, making the road “as slick as an ice skating rink.” The evidence disclosed that other cars had also gone off the road. It was dark and the ice was in an area of limited visibility, which caused people to be surprised by it. Patrolman Kinniburgh was told when he investigated the first accident *9that the road was slick and should be sanded. Usually the Maintenance Division of the Wyoming State Highway Department responds when the Highway Patrol requests that an area be sanded, and the Maintenance Division would take action if it were informed about such a hazard. The ice patch grew larger by 11 p.m., when the accident in this instance occurred. When the ambulance driver got out of his ambulance he fell down, there was difficulty in getting the gurney loaded into the ambulance, and difficulty in getting the ambulance underway. After that Officer Kinni-burgh requested the sanding of the road. He did not have to go back to the area to investigate any other accidents that night. In the light of this information in the record, we have no difficulty in concluding that there was more than sufficient evidence to entitle the jury to conclude that Kinniburgh’s conduct in not requesting that the road be sanded earlier was a substantial factor in bringing about the harm to these appellees.
The appellants’ next complaint relates to their asserted error with respect to the failure of the trial court to give the jury an instruction on the duty of care owed by Clark’s Ready Mix. Clark’s Ready Mix had been named as a defendant, but a stipulation to dismiss the complaint as to it was made prior to the trial. In assessing comparative negligence, however, the negligence of Clark’s Ready Mix had to be submitted to the jury. Board of County Commissioners of Campbell County v. Ridenour, Wyo., 623 P.2d 1174 (1981), reh. denied 627 P.2d 163 (1981). The instruction which the appellants offered with respect to the duty of Clark’s Ready Mix reads as follows:
“A landowner, such as Clark’s Ready Mix and its principals, Lynn and Lewell Clark, which is in close proximity to a public highway, must exercise reasonable care to avoid injury to the traveling public arising from unnecessarily dangerous conditions created by the landowner on the land, where the consequences of a failure to do so are reasonably foreseeable. A violation of this duty constitutes negligence.
“However, such a landowner is not considered negligent for allowing the natural accumulation of ice due to weather conditions where he has not created the condition. Further, when the danger arising from a natural accumulation of snow and ice is obvious or at least as well known to the driver of a vehicle as it is to the landowner, there exists no duty to remove the danger or warn plaintiff of its existence.”
The principles applicable in this instance are first that an instruction which is not sustained by the evidence should not be given. Hernandez v. Gilveli, Wyo., 626 P.2d 74 (1981); Beard v. Brown, Wyo., 616 P.2d 726 (1980); Gilliland v. Rhoads, Wyo., 539 P.2d 1221 (1975). Furthermore, the court should refuse to give a tendered instruction which erroneously states the law. Edwards v. Harris, Wyo., 397 P.2d 87 (1964). See Evans v. State, Wyo., 655 P.2d 1214 (1982); Nimmo v. State, Wyo., 607 P.2d 344 (1980); Simms v. State, Wyo., 492 P.2d 516 (1972), cert. denied 409 U.S. 886, 93 S.Ct. 104, 34 L.Ed.2d 142 (1972).
We agree with the trial court that the record is not sufficient in this instance to justify a conclusion that there was any unnecessarily dangerous condition created by the landowner on the land in question. The evidence was simply to the effect that the water was coming out of the approach road to the premises of Clark’s Ready Mix and onto the highway and its source may have been snow which had been plowed from Clark’s access road. The creation of the condition, however, was not specifically described by the evidence. That portion of the instruction dealing with the duty of a landowner of premises adjacent to a public way apparently derives from Timmons v. Reed, Wyo., 569 P.2d 112, 123-124 (1977), in which we said:
“The general rule applicable to the type of case now before us is stated in Restatement, Torts 2d, § 371, as follows: “ ‘A possessor of land is subject to liability for physical harm to others outside of *10the land caused by an activity carried on by him thereon which he realizes or should realize will involve an unreasonable risk of physical harm to them under the same conditions as though the activity were carried on at a neutral place.’ “The defendant, therefore, is considered to have created only a risk as to injury, and with respect to the resulting damage his conduct cannot be called anything more than negligent. [Citation.] The landowner in close proximity to a public highway must exercise reasonable care to avoid injury to the traveling public arising from unnecessarily dangerous conditions created by him on the land, where the consequences of a failure to do so are reasonably foreseeable. [Citations.] A violation of this duty constitutes negligence.” (Emphasis added.)
That portion dealing with the obvious danger rule is derived from Sherman v. Platte County, Wyo., 642 P.2d 787, 789 (1982). The instruction which was in issue in that case read:
“An owner or occupant of land or premises does not have an obligation to protect his invitees against dangers that are known to them or that are so obvious and apparent that they may reasonably be expected to discover such dangers.”
In Cervelli v. Graves, Wyo., 661 P.2d 1032, 1039 (1983), we pointed out that this instruction applies only in suits against owners of the premises and pertains to those persons who come upon the land and subsequently sue for injuries sustained because of an accumulation of ice or snow on the premises.
We hold that in these circumstances the instruction complained of did not present a statement of the law which was correct in all respects, but instead was incorrect in part, and that further part of the proposed instruction was not supported by the evidence. The district court correctly refused to give the proposed instruction.
Finally, we address the matter of costs. Specifically the appellants object to the award of costs in the following categories:
1. They complain that the bill of costs included costs for service of the summons and complaint on Jack Oakley, Lewell and Lynn Clark, and Clark’s Ready Mix, defendants with whom the plaintiffs settled. The total amount of those costs is $5.55.
2. The appellants complain of costs awarded for service of subpoenas on witnesses who were not called to testify by the appellees. Those witnesses were Charles Gaudet, Chris Brackin, Jack Oakley, Bob Zimmer, Dr. Dennis Lyman, Nanette Olsen, and Debbie Conover. The total amount of the costs awarded for service of these subpoenas was $12.00.
3. The appellants complain that costs were awarded for witness fees and mileage paid for witnesses who were not called to testify by the plaintiffs. These witnesses were Charles Gaudet, Chris Brackin, Jack Oakley, Bob Zimmer, Nanette Olsen, and Debbie Conover. The total amount of costs in issue under this item is $223.86.
4. The appellants complain that costs were awarded for witnesses for days when the witnesses did not appear at the trial. We cannot discern the amount in issue here because the position of the appellants simply is that fees were paid for more days than the witnesses actually appeared, but the one specific example simply points out that the witness testified on two days but was paid a witness fee for five days. No further specific information is given.
5. The appellants complain that expert witness fees of more than $25 per day were allowed without a showing of special circumstances for the actual payment of such fees. The amounts complained of were assessed as costs for the testimony of five physicians who testified at the trial. These amounts are significant, totaling $2,145.64.
6. The appellants complain of the award of costs for a pretrial conference with a doctor in the amount of $60.
7. The appellants complain of the award of costs for discovery depositions. These amounts total $1907.75.
8. Finally the appellants complain of the award of costs for a transcript of Kin-*11niburgh’s testimony at trial in the amount of $260.00.
The award of costs to the prevailing party is authorized pursuant to Rule 54(d), W.R.C.P., and § 1-14-124, W.S. 1977. This court previously has said that the proper costs to be assessed against the party who lost the case are not very clearly established in either the statute or the rule. Roberts Construction Company v. Vondriska, Wyo., 547 P.2d 1171 (1976). The appellants have not offered any material assistance in terms of dealing with these issues in their brief. In Hecht v. Harrison, 5 Wyo. 279, 290, 40 P. 306 (1895), the court noted that “not only must there be harm in the error, but it must be so important as to merit the consideration of the appellate tribunal, and to take something more than nominal value from the complaining party.” With respect to the specific contentions of the appellants, we hold that costs should not be awarded for service fees upon parties with whom the successful party has settled. In the absence of a showing that it was not reasonable to obtain the attendance of witnesses who ultimately were not called by the prevailing party, which the appellants have not presented in this instance, we hold that it was permissible for the district court to award costs for the service of those subpoenas. According to the provisions of § 1-14-102, witnesses are entitled to receive fees for attending before a court, and therefore even if the witness does not testify, the cost is incurred. If it was reasonable for the witness to be subpoenaed then the award of costs for attending before the court is appropriate, and we have not been directed to anything in the record which would demonstrate an abuse of discretion on the part of the district judge in awarding the costs of witness fees and mileage for witnesses who were not called. If a witness did not attend before the court then a witness fee would not be payable for that day. This record, however, does not disclose when witnesses attended, but only the days on which they testified. Consequently there was no abuse of discretion on the part of the district judge in awarding witness fees for those days on which the witnesses attended, even if they did not testify on that day. The appellants have not shown by the record that any of the witnesses for whom the fees of which they complain were paid did not attend the requisite number of days. We- shall address separately the question of the expert witness fees generally, but it does appear that, with respect to the payment of a fee for an expert witness, § l-14-102(b), W.S.1977, requires that the expert give testimony which is admitted as evidence in the ease. Therefore, the costs awarded for the physician who did not testify are not proper costs under the statute. We conclude that there was an abuse of discretion by the district court in awarding the $60 in question.
With respect to costs of discovery depositions, we espouse the rule that if the discovery deposition is reasonably necessary for the preparation of the case, then there is no abuse of discretion on the part of the district judge in awarding such costs. See for example, Bailey v. Meister Brau, Inc., 535 F.2d 982 (7th Cir.1976); Griffin v. Collins, 443 F.Supp. 1010 (S.D.Ga.1978); George R. Hall, Inc., v. Superior Trucking Co., Inc., 532 F.Supp. 985 (N.D.Ga.1982); Kraeger v. University of Pittsburgh, 535 F.Supp. 233 (W.D.Pa.1982); Wade v. Mississippi Cooperative Extension Service, 64 F.R.D. 102 (N.D.Miss.1974); Mastrapas v. New York Life Insurance Co., 93 F.R.D. 401 (E.D.Mich.1982). With respect to the exercise of discretion as to such costs, however, the burden must be upon the party seeking the award of costs to justify to the district court that those costs were reasonably necessary for the preparation of the case for trial. If the depositions are introduced at the trial, or are used for purposes of impeachment or refreshing the recollection of a witness at the trial that would ordinarily satisfy the burden of demonstrating that they were reasonably necessary. Other uses of the deposition in connection with the trial proceedings such as motions for summary judgment might serve to persuade the district court that the depositions were rea*12sonably necessary, but it would not be required to so conclude. In this instance, however, the record does not demonstrate that any of these events occurred, and the appellees made no other showing with respect to establishing that the taking of the depositions was reasonably necessary for the preparation of the case for trial. Even though many of the depositions were noticed by the appellants, the expense of a transcript also must be justified because often parties can rely upon the filed transcript in terms of preparing for trial. Because the appellees did not establish on the record that the claimed costs for depositions or transcripts were reasonably necessary to prepare the case for trial, we cannot sustain the exercise of the district court’s discretion in awarding such costs, and they must be deleted from the judgment for costs in favor of the appellees.
Substantially the same rule is applicable with respect to the award of costs for those witnesses who were subpoenaed to attend but did not testify. We note in this instance, however, that of those witnesses of whom complaint is made one of those witnesses was called by the appellants to testify. Three of them were not permitted to testify because notice of their testimony had not been given in a timely manner, but that ruling was not made by the district court until they already had appeared for trial. Finally, the conclusion not to call three of the other witnesses was reached after they had appeared and quite possibly because the trial court had indicated after the first day of trial that in its judgment negligence already had been established. Because of the familiarity of the trial judge with the dynamics of the trial, we sustain his exercise of discretion in awarding these costs.
The appellant Kinniburgh was called as an adverse witness by the appel-lees early in the trial. The appellees then obtained a transcript of his testimony for use during the trial. We are not advised by the record or the appellants’ brief as to the basis for any conclusion that this expenditure was not necessary and proper. In the brief it is argued that it was only for the convenience and advantage of plaintiffs at trial, which may not be a bad description of expenditures that are necessary and proper, and the appellants further contend that there is no authority for awarding the costs of such transcript. The trial judge obviously is in the best position to draw a conclusion as to whether this expenditure was necessary and proper. Because the appellants have failed to make any showing of an abuse of the district court’s discretion in that regard, we hold that this was a proper item of costs.
We turn to the matter of the expert witness fees with respect to which the appellants rely upon Buttrey Food Stores Division v. Coulson, Wyo., 620 P.2d 549, 20 A.L.R.4th 419 (1980). In that case we said that we did not know the amount awarded for the expert witness fee, and since there was no evidence as to the reasonableness of the unknown fee the trial court committed an abuse of discretion in awarding any amount in excess of $25. Two justices dissented because they were willing to conclude that the amount was not inappropriate for an expert witness fee for an orthopedic surgeon. In this instance the dollar amounts of the witness fees were specified, and since the record does not disclose that any complaint was made to the district court with respect to the excessive amount of those fees, the district court did not abuse its discretion in awarding these as costs. Apparently the appellants objected to the award of costs, and there is an indication that a letter was written with respect to them. That letter, however, is not a part of this record, and we do not know what the objection was that was called to the attention of the district court. It is the burden of the appellant to produce a record upon which we can decide the issues he presents. Sharp v. Sharp, Wyo., 671 P.2d 317 (1983), and authorities cited therein; Scherling v. Kilgore, Wyo., 599 P.2d 1352 (1979); Mentock v. Mentock, Wyo., 638 P.2d 156 (1981). On the limited record present we distinguish *13Buttrey Food Stores Division v. Coulson, supra.
We have found it difficult to arrive at any definitive rulings with respect to the costs in this case because our record is inadequate. We point out, however, that it is the obligation of counsel for all parties to furnish information to a trial court upon which it can make an informed exercise of its discretion. Failure to perform that obligation in the future well may lead to disal-lowance of costs that are claimed or to the allowance of costs that are resisted simply on the ground that counsel have not performed their duty to the district court.
The judgment of the district court in this instance is modified by reducing the bill of costs by $1,973.30, which will reduce the judgments of the several appellees by $657.77 each. As modified, the judgments are affirmed.