Dark green to brownish back, with dark blotches. The dark gray to black belly is an important distinguishing characteristic. The belly may have some light specks or lines on it. There are light spots along the upper and lower jaws. A large frog, 8.3 - 13.3 cm (3 1/4 - 5 1/4 in) long.
The River Frog breeds in late spring through summer. The number of eggs per female and egg clutch size are unknown. Tadpoles can be quite large, up to 15 cm (6 in.), before transformation to adulthood begins. The larger tadpoles have tails edged in black, a distinguishing characteristic, and stay in groups throughout development. It is assumed that they take at least a year for transformation. This frog is active at night, but hides in the water or vegetation at water's edge during the day. It prefers shallow, standing water, such as the edges of swamps, ponds, and slow-moving rivers. It is an opportunistic feeder and will eat worms, insects, snails, and small reptiles and amphibians. There is a record of a River Frog eating a small Eastern Diamondback Rattlesnake.
The River Frog is found throughout the Atlantic and Gulf Coastal Plain to the Fall Line.
North Carolina lists this species as being Of Special Concern. It is not listed in Georgia. Its abundance ranges from uncommon to locally common. Its distribution is related to the availability of bottomlands near swamps, rivers, and ponds. These areas must be protected to maintain populations of River Frogs.
The Pig Frog and the Bullfrog do not have light spots on their jaws, nor do they have dark bellies. Other large frogs that might be mistaken for the River Frog have dorsolateral folds, which the River Frog does not have.