Out of town recently, I ran into a couple of amphibians I don’t see often. 
This is the northern leopard frog, Rana pipiens, seen amidst its bullish and greeny brethren along the side of a road in Haverhill, MA. UPDATE 6/14: see the comments for discussion of this frog, which is probably a green frog after all.
This American toad, Bufo americanus, was also spotted in Haverhill, but at night, on the lawn. Caught here with flash as it scampered up a tree. (May last year at Doodletown we saw all the toad tadpoles.)
All around us we heard tree frogs.
I think your “leopard frog” is actually a green frog…they can be quite spotted: http://www.ohioamphibians.com/frogs/green_frog.html Lovely critter regardless!
Thanks, TGIQ. (I appreciate challenges to my IDs. ) You may be right: The tympanum here is very large, like on a green frog.
The size of the tympanum is actually a sex-based characteristic. The frog in your photo is a male, since the tympanum is larger than the eye; if it was a female it would be smaller than the eye. 🙂