Boreal chorus frog (male)

It's a slim, small frog. It has three gray to dark brown stripes or lines of dark spots on the lighter background color of the back. There is a pale stripe above the lip and a thicker dark stripe above the pale stripe that extends from the tip of the snout, past the tympanum, and often down the side of the body. The belly is pale with a few small spots. (taken from "A Field Guide to Oklahoma's Amphibians and Reptiles")