The river redhorse is a moderately chubby, coarse-scaled sucker with a short dorsal fin. The lower lips are broken up into parallel folds. The rear margin of the lower lip forms a slight V-shaped angle. The scales of the back and upper sides each have an indistinct crescent-shaped dark spot at the base. The base of the tail fin has a thin pencil-line of black along the hind margin of the last row of scales. The tail fin is bright red in life, and the upper lobe of the tail fin is often slightly longer and more pointed than the lower lobe.
Overall coloration: Back and upper sides olive brown with golden reflections, the scales rather prominently dark edged; remainder of sides a rich golden yellow. Belly white. Dorsal fin olive or slate; tail fin bright red; lower fins plain or with orange tinge.
Breeding males have small tubercles on the head, body, and fins, with these best-developed on the snout and cheeks.
More characters: Dorsal fin contains 12 or 13 (rarely 14) rays. The lateral line is complete, with 41–46 scales. The outer margin of the dorsal fin is straight or slightly curved outward (convex). The throat teeth on the lower half of the first arch are few in number, broad and molar-like, and with flattened grinding surfaces. The air bladder has 3 chambers.
Similar species: Overall, the coloration is similar to the shorthead redhorse. The shorthead redhorse, however, has the rear margin of the lower lip nearly straight; has a shorter head (its length, from tip of snout to outer edge of gill, goes 4.5 times or more into the standard length, from tip of snout to base of tail); has the upper lip often with a pea-shaped swelling at the middle; and has the throat-teeth arch thin, with slender teeth in comb-like series (not thick, with molar-like teeth).