Apodemia mormo (Mormon metalmark) is a principally Nearctic butterfly in the family Riodinidae. It is a particularly fascinating species for ecological and evolutionary research, as evidenced by its shifting taxonomic classifications. Conflicting observations of host plants utilized, distinctive morphologies, and a wide range of occupied habitats have prompted investigation into several potential subspecies. To date, two genetic studies have been done on A. mormo, with analysis revealing that disjunct populations are genetically and phenotypically distinct. These studies support a potential need for refined taxonomies, although a larger body of data is required to make clear decisions. Populations of A. mormo are widely distributed throughout western North America, with peripheral colonies located in Canada and Mexico. The Canadian populations have historically lacked scientific study, prompting a series of investigations in the past decade. A. mormo is the only representative of the family Riodinidae, a primarily Neotropic family consisting of roughly 1500 species, that lives in Canada. Three populations of A. mormo have been given conservation statuses: the Saskatchewan population is listed as threatened, while both the British Columbia and Comstock Lange populations are classified as endangered. Conservation efforts are complicated by a dependency on human activity for habitat success. Soil disturbances, caused by human and railway traffic, are critical for the survival of host plants and subsequent A. mormo populations; however, overbearing human presence can lead to habitat destruction. Conservation statuses have been repeatedly defended by research, and recovery strategies developed in response. Geographic range Apodemia mormo constitutes the widest ranging North American species of the family Riodinidae. Populations of A. mormo span western North America, ranging from Sinola, Mexico to Southwestern Canada, and are found west of North Dakota primarily in California, Utah, Arizona, New Mexico, and Washington. While there are several populations recognized in the US, only two are present in Canada: the British Columbia population, along the Similkameen River Valley, and the Saskatchewan population, in the Grasslands National Park. The Canadian populations are listed with conservation statuses of “endangered” and “threatened”, respectively. Rather than a continuous distribution, A. mormo colonies occur in semi-isolated patches. Population studies have found that small amounts of geographic distance between colonies (15–20 km) are significant to hinder gene flow, and render populations phenotypically distinct. Thus, there is great within species variation depending on geographic location, and taxonomic distinctions are still in flux. Habitat Populations of Apodemia mormo primarily occupy dry, arid habitats that