The Largescale is a typical sucker of the elongated variety, with an underslung mouth and a torpedo-shaped body. This is a west-slope fish, ranging across the northern rockies as far east as the continental divide but no farther. It's a fairly large species of fish, topping out at around 5 or 6 pounds, with a brownish-gray back and a sharply contrasting white belly.

Like most of its catostomid relatives, the Largescale Sucker can be caught on a variety of small baits or lures, with worms being the overwhelmingly most effective bait choice. Flies imitating small aquatic nymphs are quite effective. Like the rest of the suckers, it's a tasty but bony fish that has sweet, white meat.