Abstract Esmeralda County, Nevada, is extraordinary for the presence of Ediacaran and early Cambrian reefs at several stratigraphic positions. In this road log and field guide we present descriptions and interpretations of the most instructive exposures of three of these reef-rich intervals: (1) the Mount Dunfee section of the Middle Member of the Deep Spring Formation (Ediacaran in age), (2) the Stewart's Mill exposure of the Lower Member of the Poleta Formation (mid-early Cambrian), and (3) an exposure on the north flank of Slate Ridge of reefs near the top of the Harkless Formation (latest early Cambrian). We introduce the term “congruent ecosystems” for ecosystems of different age that occupied similar environments. The Ediacaran reefs of the Deep Spring Formation and the early Cambrian reefs of the Lower Member of the Poleta Formation occupied similar environments but exhibit distinctively different ecological structure. Thus we propose these two reef complexes as our premier example of non-congruent communities within congruent ecosystems.