To understand dynamics within communities of organized interests, researchers have primarily studied organizational births and deaths. The organizational development of established interest organizations has received far less attention. This article claims that the evolution of interest groups' organizational features is strongly affected by evolving resource dependencies with the state. A life-history case study of an environmental interest organization is used to substantiate this argument empirically. The findings demonstrate that resource dependence relations with state actors critically shape organizational development, but that this dependence affects an organization's mission, structure, and strategy in different ways. This conclusion highlights the vital role of government patronage in the survival and maintenance of interest organizations.