It occurs in the cordilleras of Tilarán, Central, and Talamanca in Costa Rica as well as adjacent western Panama.

[1][2] The species was thought to already have become extinct, but in 2007, it was re-discovered in the Monteverde Cloud Forest of Costa Rica when a single male was found.

The toes have discs that are slightly smaller than those on the fingers and are two-thirds webbed.

[4] Isthmohyla rivularis is found along or in clear streams in lower and premontane rainforests at 1,210 to 2,040 m (3,970 to 6,690 ft).

Also habitat loss caused by agriculture and selective logging have impacted the species.