North America east of the Rocky Mountains (map
). Widely distributed in the eastern USA but no records from northern New England (unrecorded from ME, VT, and also RI) or from lowlands of the southeastern coastal plain (no confirmed records from SC, though likely occurs there at higher elevations, or from MS and FL. Recorded from all central states except LA and in eastern MT, WY, and CO (replaced in the west of those states by B. nevadensis
). In Canada restricted to the south where known from southern Ontario. It may occur west at least to Manitoba, but its distributional limits to the west has been obscured by convergence in color pattern with B. nevadensis
). Distributional summary by John S. Ascher (Feb 2014).