True to its name, the Cascades Frog (Rana cascadae) lives high up in the great mountain range of the northwest. Large populations of this frog also exist in the Olympic and Klamath Mountains. It’s one of the amphibians you’re most likely to see while hiking in the high country, especially when your trail passes through a subalpine meadow.
If a Cascades Frog sees you first– and with its large eyes and wide field of view, it probably will– you might only hear a little splash as the frog dives into the nearest pond. It will bury itself in the muck on the bottom of the pond or hide under overhanging vegetation along the shore, re-emerging only after you’ve gotten impatient and walked on.
This frog is near and dear to my heart. It’s one of the amphibians I studied in graduate school at Oregon State University. I spent many adventure-filled days looking for Cascades Frogs in wild places. Years later, I’m still thrilled every time I see one sitting at the edge of a pond or hopping along a streambank.
Adult Cascades Frogs are 1-3 inches (25-75 mm) in length. They have brown or tan skin, mottled with irregular dark spots and blotches. A dark ‘mask’ is usually present around the eyes and the upper lip is a light cream color.
Cascades Frogs can be confused with two of their close relatives: the Red-legged Frog and the Oregon Spotted Frog. Red-legged Frogs generally live in lowland valleys rather than in the mountains. They have few dark markings on their backs and have translucent pink skin on the undersides of their legs. The Oregon Spotted Frog is relatively rare, but it does live in some of the same mountain habitats as the Cascades Frog. Spotted frogs have eyes that are more upturned, compared to the other two species, and they have bright orange or reddish coloring on their undersides and legs.
The season of sunny, ice-free days is relatively short in the mountains. Cascades Frogs have to breed early in the summer so that their tadpoles have time to metamorphose into froglets before the snows return in fall. Small pothole ponds in wet meadows are the preferred breeding habitat. These have few aquatic predators that could eat the frogs or their tadpoles. Breeding begins as soon as the ice begins to melt at the edges of ponds and lakes. Males make quiet, chuckling calls underwater and breed with whatever females they can grab onto.
The adults move between ponds, lakes, and small streams in summer as they fatten up on insects and other invertebrates. In fall, they move to larger lakes where they burrow into the muddy shallows to hibernate through the snowy winter.
Like many amphibians, the Cascades Frog has disappeared from parts of its range. Direct habitat destruction by humans is probably not the main factor contributing to this species’ decline, since it lives in remote mountain environments. Introduced fish predators and human-spread disease are more likely to be the problem. The meadow habitats of the Cascades Frog may be shrinking and disappearing as the climate warms up. As the meadows are lost, so are the frogs.
For now, Cascades Frogs are still common in wet subalpine meadows across the mountains of the northwest. If you want to see this charming amphibian up close, walk slowly as you approach a mountain pond and scan the shoreline. You might be lucky enough to see a Cascades Frog sitting among the vegetation– before it sees you.