Frogs and Toads of New Hampshire
The Eastern Gray Tree Frog and the Spring Peeper are the only tree frogs in the state. The Gray Tree frog is much larger than the Spring Peeper and the Spring Peeper has a x shaped mark on its back.
True Frog Family – Ranidae
The Bullfrog and Green Frog can be distinguished from each other from the dorsal ridge. The Green frog has a line that goes almost all the way down its back while the Bullfrog’s line wraps around the ear.
The Mink Frog (Lithobates septentrionalis) has the dark black on its back that makes it easy to tell apart from the other frogs in this state.
The Pickeral Frog and Northern Leopard Frog look very similar to each other because of the spots but the Pickeral frog’s spots are more rectangular than the Northern Leopard Frog.
Wood Frog (Lithobates sylvaticus) is easily id’d by the mask around its eyes.
Best way I’ve found to tell apart Fowler’s Toad and American Toad’s is this image.