Adult Oregon spotted frogs have moist bumpy skin that is reddish-brown on their topsides. On their heads, backs, sides and legs, they have black spots with light centers that darken with age. They also have red bellies and orange-red underlegs. Adult females grow to four inches in length and males to three inches.
Oregon spotted frogs live in wet areas that provide abundant aquatic vegetation such as marshes, permanent ponds, lake edges and slow streams. When frightened, they hide in dense vegetation or under debris at the bottom of shallow wetlands. Adult frogs hibernate during the winter in freeze-free seeps, springs and channels (sometimes in mud bottoms at least one foot under water) connected to their breeding waters.