Likely transcontinental distribution; species complex.Recorded on Richards Island, NWT. Francoeur (1997) lists two unnamed species of Leptothorax as occurring in the Yukon. Widely distributed species, appears to be able to inhabit many habitat types including boreal coniferous forests, dry Ponderosa Pine (Pinus ponderosae) forests, woodlands and other forest types. Considered to be a highly cold-tolerant boreal-alpine species (Wheeler and Wheeler 1986). Palearctic.Should be revised in 5 years. L. muscorum is a complex for which the species muscorum is not present in NA and that also refers to several other undescribed species. The names La. alienus, La. flavus, La. umbratus, Le. muscorum, and F. fusca are restricted to Palearctic populations of these taxa (Schär et al., 2018). The North American members of the genus Leptothorax are a difficult species complex whose taxonomy remains unresolved. Taxonomists have the knowledge to solve this complex, but it has not been revised nor published so far.