It is generally olive green or brown above, with pale underparts, and breeding males have a lateral red-orange band and fins suffused with the same color.

Breeding takes place in late spring and early summer in gravelly riffles in small streams.

This is a slender and streamlined sucker, generally olive green to brown above and on the sides, and white to yellowish underneath.

While suckerfish in general live in a variety of habitats, the mountain sucker tends to favor clear water streams with a moderate gradient, with widths of 3 – 15 m and depths of less than 2 m, and rocky or gravelly bottoms.

Mountain suckers are primarily herbivorous, feeding mostly on algae and diatoms, but they will eat various aquatic invertebrates as well.