The U.S. Geological Survey recognizes six major plays for nonassociated gas in Tertiary and Upper Cretaceous low-permeability strata of the Uinta Basin, Utah. For purposes of this study, plays without gashater contacts are separated from those with such contacts (i.e., continuous-saturation accumulations). Continuous-saturation accumulations are essentially single fields, so large in areal extent and so heterogeneous that their development cannot be properly modeled as field growth. Fields developed in gas-saturated plays are not restricted to structural or stratigraphic traps and they are developed in any structural position where permeability conduits occur such as that provided by natural open fractures. Other fields in the basin have gas/water contacts and the rocks are water-bearing away from structural culmination's. The plays can be assigned to two groups. Group I plays are those in which gas/water contacts are rare to absent and the strata are gas saturated. Group IT plays contain reservoirs in which both gas-saturated strata and rocks with gas/water contacts seem to coexist. Most units in the basin that have received a Federal Energy Regulatory Commission (FERC) designation as tight are in the main producing areas and are within Group I plays. Some rocks in Group II plays may not meet FERC requirements as tight reservoirs. However, we suggest that in the Uinta Basin that the extent of low permeability rocks. And therefore resources, extends well beyond the limits of current PERC designated boundaries for tight reservoirs. Potential additions to gas reserves from gas-saturated tight reservoirs in the Tertiary Wasatch Formation and Cretaceous Mesaverde Group in the Uinta Basin, Utah is 10 TCF (Group I sum of means of plays). If the potential additions to reserves in strata in which both gas-saturated and free water-bearing rocks exist (Group IT plays sum of means) are added to those of Group I plays, the volume is 13 TeF. Of this latter number, as much as 7.4 TCF will be recovered from Tertiary reservoirs and 5.8 TCF from Upper Cretaceous rocks.