Recently it has become clear that habitat use by the salt marsh harvest mouse is quite flexible. But that begs the question, if SMHM do not REQUIRE pickleweed, why are they mostly restricted to marsh habitat? And why are SMHM abundant in marshes during some years, and rare during other years? And what about all those other rodents we catch? These are the kinds of questions that can only be answered with long term, comprehensive datasets collected during periods of diverse conditions. The most comprehensive multi-year study in the last decade occurred only during drought conditions, which was great for looking at the impacts of habitat and competition, but not at teasing out the impacts of other environmental factors, most importantly, precipitation. An inability to account for weather has hindered our ability to evaluate historical datasets, but data collected in the past five years has begun to illuminate the impacts of precipitation, revealing that some substantial impacts of wet winters may not be realized until over a year later. Even more interestingly, those impacts seem to be influenced by competition, by way of habitat. Here we present the interaction between weather, habitat, and competition, and discuss impacts on SMHM conservation.