I test the hypothesis that religious affiliation is an empirical measu
re of tastes and beliefs that affect the demand for membership in envi
ronmental citizen groups. The number of adherents to Judeo-Christian d
enominations per household has a significant, negative effect on state
membership rates for nine groups advocating a preservationist approac
h to environmental policy, particularly in states with many Catholics,
Baptists and Mormons. Religious affiliation has a marginally signific
ant, positive effect on membership rates for two sportsmen groups advo
cating private stewardship. These results suggest that religious affil
iation should also be a significant determinant of constituent prefere
nces for environmental policies.