Since 1940, Idaho Department of Fish and Game has developed a network of 31 Wildlife Management Areas (WMAs) across the state. This program has been focused mostly on conservation of game species and their habitats. We assessed the contribution of Idaho's WMAs to conservation of all Idaho's wildlife and other aspects of ecological diversity. Predicted occurrences of species' breeding habitats and other data were used to evaluate the representation of wildlife habitat and other ecological conditions. We found 33 of 39 natural land cover types were mapped as occurring in WMAs. WMAs occurred in 10 of 15 of Bailey's ecoregion sections, absent only from two sections that occupy greater than 1% of Idaho. Percent area of WMAs by elevation followed a pattern similar to percent area of Idaho; however, mean elevation for WMAs was lower than for the state and other protected areas in Idaho. We predicted breeding habitat for 98.4% of Idaho's wildlife and all federal and state listed threatened, endangered, or candidate terrestrial vertebrates to occur in at least one WMA. We predicted habitat for 39 species to occur on five or fewer WMAs, and predicted no habitat on WMAs for five species. We found that a system of WMAs established mainly to protect game species potentially conserves many other aspects of Idaho's ecological diversity, may provide habitat for more than 98% of Idaho's wildlife, and complements other protected areas in the state.