The concept of mapping religion and then acting on the basis of that c
oncept necessarily involves discussion of another concept, that of bou
ndaries. The notion of discerning neat boundaries serves well for asse
ssing the inherited institutions of religion in America; assessments o
f trends within them reveal impressive continuities in organization an
d structures of meaning. Many of the most important religious developm
ents in the last third of the century, however, appear to be less boun
ded-or even unbounded-and on the blurry landscape of boundarylessness
there are more evident discontinuities, innovations, and evidence of f
luidity. An analysis of several trends on the unbounded landscape sugg
ests that, in the new century, there will be a great deal of interchan
ge and conflict between these two ways of conceiving American religiou
s dynamics.