4 natural gas statistics dry proved reserves the united states had 183 460 billion cubic feet of as december 31 2001 a 3 percent increase over 2000 level table 8 all data shown in this report exclude held underground storage most reserve increases were wyoming colorado and texas owing to drilling or improved stimulation technology used madden wattenberg pinedale fields coalbed methane barnett shale lobo trend areas utah new mexico which significant smaller gains california s oklahoma declined despite last year additions 25 812 11 less than operators replaced 131 production figure 18 us total discoveries 22 758 up 19 from 138 by state are on map
