Shawnee State Forest last weekend was perfect for catching the short-lived eruption of breeding Mountain Chorus Frogs, Pseudacris brachyphona. This species is far more limited in its distribution in Ohio than is the more familiar Western Chorus Frog, P. triseriata, which occurs nearly statewide. The latter makes a characteristic grating rasp, often said to resemble the sound of a fingernail run down the teeth of a comb.
Mountain Chorus Frogs make more of a short bleating trill - faster and higher-pitched than the Westerns. They also occur in heavily wooded areas and are limited to the unglaciated hill country of southeastern Ohio. I've never heard Mountains and Westerns together, and doubt that their paths would typically cross given the differences in habitat.
The above photo shows a typical Mountain Chorus Frog breeding pond. These frogs are prone to selecting tiny ephemeral pools, often little more than water-filled tire ruts in some cases.
Like most other frog species, when a large human blunders near the mating pool, all of the frogs go silent and dive into the muck. With a little still and quiet patience, they'll soon pop back out and commence activities. This pair was so enthralled with one another that they never even hid, and I was able to sneak quite close without alarming them. The male (top, obviously) is locked in amplexus with the reddish-brown larger female. Note the length of her toe!