The fronds of Thelypteris simulata are spread out along a rhizome, and are therefore not conspicuously clumped, though consectutive fronds may be only 1-2 cm apart. The blades are pinnate-pinnatifid and 14-35 cm long. Sori are round with true indusia. Veins in the blade segments are unbranched, in contrast to the very similar T. palustris for which the veins are branched.

T. simulata ranges from Nova Scotia and Ontario to Virginia and West Virginia. It is disjunct in Wisconsin where it is known from 5 contiguous counties in the west central portion of the state. It is listed as a special concern species in Wisconsin. Habitat is usually wet forest on acid soils.