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Medium-size (3.0-4.2 cm wingspan) broad-winged brown (female) or brownish-grey (male) moths. Males have two dark bars crossing the forewing, the innermost curving outward near the lower margin, but touching neither the outer band nor the lower margin of the wing. The subterminal band is reduced to a few small points except near the costa, where it forms two prominent black fused spots. The hindwing is light grey-brown with a dark sinuous subterminal band and dark terminal band. The female is dull grey-brown with the bars of the male forewing reduced to faint lines. The hindwing is also brown, and the terminal bands are much less contrasting than those of the male. In the smaller and more common C. crassiuscula the forewing bars are wider and usually touch at the bottom, while the antemedian bar runs straighter and usually touches lower margin. Females of crassiuscula are smaller, browner and much more strongly marked than those of erechtea. Some males of the two species can be very difficult to identify, and the genitalia need to be examinined.

Throughout most of the United States and Canada from Quebec west, north at least to the southern edge of the boreal forest in western Canada. Widespread in the southern half of Alberta, from the Milk River north to at least the Nordegg, Edmonton and Lloydminster areas.