This is an uncommon moth (previously named Acronicta dactylina), but is widely distributed throughout the United States and southern Canada. The caterpillars are found mostly in deciduous and mixedwood forests, feeding on alder, birch, poplar, hawthorn, and willow. This caterpillar will soon enter the pupa stage and will overwinter in leaves or debris protected in its cocoon.
Photo by Carmen Smith on 9/14/20 in Norris, MT