Pseudocopaeodes eunus is a rare species of butterfly known by the common name alkali skipper. It is native to northern California and Nevada in the United States, and Baja California in Mexico. There are five subspecies. One, ssp. obscurus, the Carson wandering skipper, is treated as a federally listed endangered species of the United States. As of 2007 there are four known populations. This butterfly is brownish to yellowish orange on the upper side and yellowish below. It is 2.5 to 3.2 centimeters in length.