OPINION
ZAPPALA, Justice.The question presented by this appeal is which of the parties to a coal severance deed, or more precisely which of their successors in interest, is to be recognized as owner of coalbed gas. The Superior Court affirmed a final decree of the Court of Common Pleas of Greene County and quieted title to the gas in favor of the surface owners, permitting them to lease rights to drill into the coal seam to extract the coalbed gas contained therein, subject to restrictions imposed to prevent unreasonable damage to the coal owner’s property. U.S. Steel v. Hoge, 304 Pa.Super. 182, 450 A.2d 162 (1982).
The Appellant, United States Steel Corporation (hereinafter “coal owner”), is owner of the “Pittsburgh” or “River” Vein of coal underlying certain tracts of land in Greene County owned by Appellees Hoge, Cowan, and Murdock (hereinafter “surface owners”). This coal seam is located *144approximately 800 feet beneath the earth’s surface. Appellant’s predecessor in title acquired rights to the coal from Appellees’ predecessors in title via a severance deed dated July 23, 1920.
The' deed, which contained language common to most coal severance deeds executed in 1920 and in later years, read in pertinent part as follows, conveying
All the coal of the Pittsburgh or River Vein underlying all that certain tract of land...
Together with all the rights and privileges necessary and useful in the mining and removing of said coal, including the right of mining without leaving any support ..., the right of ventilation and drainage and of access to the mines for men and materials...
The parties of the first part [surface owners] hereby reserve the right to drill and operate through said coal for oil and gas without being held liable for any damages.
Together with all and singular the improvements, ways, waters, water courses, rights, liberties, privileges, hereditaments and appurtenances... (Emphasis added)
In 1976 and 1977, Appellee Cunningham (hereinafter “gas lessee”) acquired all of the foregoing reserved gas and oil rights from the surface owners. In 1978, the gas lessee began drilling wells for the purpose of recovering coalbed gas from the “Pittsburgh” coal seam. Upon learning of the drilling operations and the gas lessee’s intention to stimulate recovery of coalbed gas through a process known as hydrofracturing,1 the Appellant coal owner initiated actions in equity to terminate the intrusion upon its coal seam and to determine the ownership of, and right to develop, the coalbed gas. The chancellor entered a decree permitting *145the drilling for such gas in Appellant’s coal seam, but prohibiting the use of hydrofracturing methods to stimulate gas recovery. Superior Court affirmed.
The ownership of, and right to develop, coalbed gas are questions of first impression. Consideration of the characteristics, origins, and history of development of gas is necessary to a determination of the issues presented. The following factual background is condensed from the chancellor’s findings. Coalbed gas is found in and around coal veins, having long been recognized by the mining industry as a highly combustible and deadly poisonous gas which must be, at all times during the active coal mining process, ventilated to prevent explosion or inhalation; hence, the gas has traditionally been wasted into the atmosphere. Coalbed gas is always present in coal seams; its molecules are absorbed in micropores of coal, and even the smallest particle of coal always contains, and when exposed emits, some coalbed gas. Coal and coalbed gas are, nevertheless, separate physical entities.
The gas which has commonly been referred to as “natural gas” is generally found in strata deeper than coal veins, though it shares many of the characteristics of coalbed gas. Both gases evolved, through natural processes, from carbonaceous material beneath the earth’s surface, and both contain mixtures of various hydrocarbons, including methane, ethane, propane, butane, carbon dioxide, carbon monoxide, and hydrogen sulfide. Both are, as are all gases, migratory, thus being capable of escaping their natural habitats to enter other strata, and both are found in the same geographic areas of Pennsylvania. Due to its fugacious character, natural gas is capable, under certain circumstances, of commingling with coalbed gas in the upper strata.
Natural gas and coalbed gas have value as energy sources, the latter having approximately a 90 percent heating value as compared to the former. The energy value of the coalbed gas is far less, however, than that of the coal *146itself; the value of the coalbed gas is only one percent of the b.t.u. value of the coal.
Extensive and costly drilling operations are required in order to extract coalbed gas or natural gas from strata where they are found. As early as the year 1900, certain wells were drilled in Greene County into the subject Pittsburgh Vein of coal, and not deeper, and some of these wells produced coalbed gas in paying quantities. Commercial exploitation of coalbed gas, however, has remained very limited and sporadic until recently. As a result of our nation’s high energy demands and shortage of energy supplies, conditions which gained much attention during the past decade, both the gas industry and the mining industry have come to regard coalbed gas as having sound market potential. There has recently developed an industrial capacity to drill into coal seams both horizontally and vertically to recover coalbed gas. With either drilling approach, the process of hydrofracturing facilitates recovery of coalbed gas in greater volumes and over longer periods of time. Nevertheless, in some areas coalbed gas can be recovered in paying quantities without any artificial stimulation of the coal seam. As noted previously, certain gas companies have through the years produced coalbed gas from wells in Greene County and in other portions of western Pennsylvania. More recently certain coal owners, including Appellant, have drilled into and in some cases hydrofractured their own coal seams in various regions — as experimental determinations of coalbed gas production capacities and as a means of alleviating the presence of the gas in areas soon to be mined. Against this background, we examine the ownership and development rights to coalbed gas.
The fact that gas is of a fugacious character does not prevent ownership in it from being granted prior to its being reduced to possession. We have long recognized that gas may be owned prior to being recovered from its natural underground habitat. Hamilton v. Foster, 272 Pa. 95, 102, 116 A. 50, 52-53 (1922). Gas is a mineral, though not commonly spoken of as such, and while in place it is part of *147the property in which it is contained, as is the case with other minerals within the bounds of a freehold estate. Id. Gas necessarily belongs to the owner in fee, so long as it remains part of the property; ownership in it will be lost only upon grant or upon the gas leaving the property through migration. Id. In Westmoreland & Cambria Natural Gas Co. v. DeWitt, 130 Pa. 235, 249, 18 A. 724, 725 (1889), the governing principle of gas ownership was stated as follows:
Water and oil, and still more strongly gas, may be classed by themselves, if the analogy be not too fanciful, as minerals ferae naturae. In common with animals, and unlike other minerals, they have a power and a tendency to escape without the volition of the owner ... They belong to the owner of the land and are part of it, so long as they are on or in it, and are subject to his control; but when they escape and go to other land, or come under another’s control, the title of the former owner is gone. (Emphasis added)
Thus, as a general rule, subterranean gas is owned by whoever has title to the property in which the gas is resting. Cf. Kier v. Peterson, 41 Pa. 357 (1862) (owner of subterranean salt entitled to oil commingled with it). But cf. Erwin’s Appeal, 7 Sad. 477, 12 A. 149 (Pa.1887). When a landowner conveys a portion of his property, in this instance coal, to another, it cannot thereafter be said that the property conveyed remains as part of the former’s land, since title to the severed property rests solely in the grantee. In accordance with the foregoing principles governing gas ownership, therefore, such gas as is present in coal must necessarily belong to the owner of the coal, so long as it remains within his property and subject to his exclusive dominion and control. The landowner, of course, has title to the property surrounding the coal, and owns such of the coalbed gas as migrates into the surrounding property.
We do not regard as inconsistent with this analysis the fact that the coal owner’s interest in the situs occupied by the coal may be less than perpetual. In addressing *148questions of title to coal, and of rights of access to and through coal to secure its removal, this Court has not construed the conveyance of coal alone as a grant of a fee simple estate in the situs where the coal is located. Rather, the coal owner’s interest in that situs has been regarded as being in the nature of an estate determinable, which reverts to the surface landowner by operation of law at some time subsequent to removal of the coal. Webber v. Vogel, 189 Pa. 156, 160, 42 A. 4, 5 (1899); Chartiers Block Coal Co. v. Mellon, 152 Pa. 286, 296-297, 25 A. 597, 599 (1893). The potential for reversion of the situs, however, does not diminish the character of the coal as property of its grantee, or of the gas contained therein as a mineral ferae naturae resting inside the coal owner’s property and falling within the dominion and control of the coal estate. The owner of coal may, as may any property owner, exercise dominion over his property so as to maximize his right of enjoyment thereover, within bounds limiting impingement upon the rights of other property owners. Chartiers Block Coal Co. v. Mellon, 152 Pa. at 295, 25 A. at 598. Hence, the coal owner may mine his coal, extract the gas from it, or both. If he chooses to extract the gas, drilling as well as hydrofracturing are available means, so long as their utilization does not impinge upon the rights of owners of the surrounding property, since the damage to coal inflicted by these processes is within his dominion to inflict.
Although coalbed gas contained in coal is, ab initio, property of the coal owner, that owner may allow others certain rights respecting the gas. In the present case, the grantor of the coal severance deed reserved therein the “right to drill and operate through said coal for oil and gas without being held liable for any damages.” In construing the extent of the rights thereby reserved, effect should be given to the intentions of the parties to the instrument. In re Conveyance of Land Belonging to City of Dubois, 461 Pa. 161, 169-170, 335 A.2d 352, 357 (1975); Dunham & Shortt v. Kirkpatrick, 101 Pa. 36, 43-44 (1882) (severance of mineral rights). The language of the deed should be *149considered in its entirety, giving effect to all its terms and provisions, and construing the language in light of conditions existing at the time of its execution. In re Conveyance of Land Belonging to the City of Dubois, 461 Pa. at 169; 335 A.2d at 357; St. Michael & Archangel Russian Orthodox Greek Catholic Church v. Uhniat, 451 Pa. 176, 186, 301 A.2d 655, 660 (1973). The plain meaning, in the common understanding, of the provisions in a severance deed has been utilized as the best construction, where it may safely be assumed that such was the understanding which the parties themselves accorded the terms. Dunham & Shortt v. Kirkpatrick, 101 Pa. at 44. In accordance with these rules of construction, and in light of the chancellor’s findings of fact as to the circumstances surrounding the deed’s execution, the instant severance deed in question may be examined for evidence of the parties’ intent.
As found by the chancellor, at the time this coal severance deed was entered into, although commercial exploitation of coalbed gas was known such operations were very limited and sporadic. Indeed for the most part coalbed gas was a dangerous waste product which had to be vented from the coal seam to allow for safe mining of the coal. This common practice is attested to by the presence in the deed under consideration of a “right of ventilation”, permitting the grantee of the coal severance deed the right of reasonable encroachment on the estate retained by the grantor for the purpose of ventilating the gas from the coal seam.
The reservation to the grantor of the right to drill through the coal seam deeded away for oil and gas is stated generally. Although the unrestricted term “gas” was used in the reservation clause, in light of the conditions existing at the time of its execution we find it inconceivable that the parties intended a reservation of all types of gas. In so finding, we are unable to overlook a basic question: Why would a party retain the right to something which is only a waste product with well-known dangerous propensities? Case law is replete with examples of terms coming to have *150recognized meanings either more or less inclusive than they have in common parlance, usually through usage of the particular parties involved or the attendant business or industry. We find implicit in the reservation of the right to drill through the severed coal seam for “oil and gas” a recognition of the parties that the gas was that which was generally known to be commercially exploitable. It strains credulity to think that the grantor intended to reserve the right to extract a valueless waste product with the attendant potential responsibility for damages resulting from its dangerous nature. See McGinley, Legal Problems Relating to Ownership of Gas Found in Coal Deposits, 80 W.Va.L.Rev. 369, 391 (1978). We find more logical and reasonable the interpretation offered by the Appellant that the reservation intended only a right to drill through the seam to reach the unconveyed oil and natural gas generally found in strata deeper than the coal.
The order of the Superior Court is reversed, and the case is remanded to the Court of Common Pleas of Greene County for entry of a final decree quieting title in the Plaintiff-Appellant, United States Steel Corporation.
FLAHERTY, J., filed a dissenting opinion in which HUTCHINSON, J., joined.. Hydrofracturing is the forcing of fluids under pressure into the well so as to cause a fracturing of the target stratum. When applied to coal seams, the process creates fractures in the coal which serve as conduits through which gas can flow through the seam to the well’s shaft. Developed by the drilling industry in the late 1940’s, hydrofracturing was initially utilized to recover natural gases from strata other than coal veins, and has more regularly been so used.