This paper examines foundings of human services organizations after natural disasters such as floods, earthquakes, wildfires, hurricanes, and tsunamis and explains why only some communities bounce back by founding appropriate collective-goods organizations. Using natural disasters in California counties from 1990 to 2010 as shocks that exogenously impose a need for collective goods over and above the level endogenous to the community, this paper shows that a geographic community’s local organizing capacity rests on the richness of its repertoire of voluntary organizing models as reflected in the diversity of its voluntary associations. Such diversity is even more critical when the type of natural disaster is more unexpected or complex (e.g., both a wildfire and an earthquake) in an area, and the organizational challenges posed are thus more novel for the community. Associational diversity has positive effects on both the numbers and aggregate size of foundings of local (non-branch, secular) human services organizations, and the effects are generalizable to other endogenous demand conditions such as poverty. Results also show how different kinds of variety can have opposing effects on organizing capacity after a disaster, with associational diversity having a positive effect, political diversity having a negative effect, and racial diversity having no significant effect, net of other factors. The paper concludes with a call for treating community resilience as a matter of enhancing local organizing capacity over centralized planning efforts when the environment is rapidly changing.