It is a well established fact that discoveries of natural gas in Western Canada have declined over the last 30 or so years. However, statistical analyses of the declining trends have, to date, failed to provide a generally acceptable estimate of the conventional natural gas resources of the Western Canada Sedimentary Basin. This paper provides an explanation of why decline analysis appears to provide a valid method for estimating the conventional crude oil resources of the basin while the same is not true for natural gas. The paper proposes solutions to the problems encountered in the natural gas data and provides an estimate of the conventional natural gas resources of the basin by statistical analysis of the declining discovery rate trends.