Male Dun Skippers have unmarked chocolate brown wings. They often have a golden color on the top of the head, which is a good field mark in fresh individuals. 

Female Dun Skippers sometimes have a few faint white spots on their wings. 

Dun Skippers are usually unmarked brown below, although they can occasionally have a faint band of small white dots. Dun Skippers fly from June through September. 

Little Glassywings can be distinguished from Dun Skippers by the large white squares on the upper surface of their wings. 

Little Glassywings usually have a band of white spots on the ventral surface of their wings (sometimes faint). Also, Little Glassywings have a white-colored patch on their antennae, just below the antenna club. Little Glassywings fly from June through August. 

The butterfly at left is my only sighting of a Northern Broken-Dash. These butterflies are apparently less common than Dun Skippers and Little Glassywings in our area. Northern Broken-Dashes usually have a stronger spot band on the undersurface of their wings. This individual was photographed at Cox Arboretum on August 16, 2020. 

This Dun Skipper looks reddish-brown in this light, but Dun Skippers usually look darker brown. 

Northern Broken-Dash with its wings spead. This is the same individual as above. Notice that the spots are narrow, rectangular, and elongated, compared with the large square spot on the Little Glassywing further above. 

This Dun Skipper is more faded than the very fresh individual above.