Isthmohyla rivularis is a rare species of frog in the family Hylidae. It occurs in the cordilleras of Tilarán, Central, and Talamanca in Costa Rica as well as adjacent western Panama. 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. In 2008, a gravid female and few males were spotted. The common name American Cinchona Plantation treefrog has been suggested for it.

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