I visited Long Lake (43°43’16.45” N 113°50’06.40” W) over the weekend and took pictures of a frog. I have a Peterson Field Guide for Western Reptiles and Amphibians, second edition. The frog looks like the mountain yellow-legged frog shown on Plate 14 (and I would be happy to supply pictures but I don’t see a way to attach a picture here). The field guide says that mountain yellow-legged frogs do not occur in Idaho.
No, the mountain yellow-legged frog does not occur in Idaho. However, we do have a closely related species called the Columbia spotted frog, which looks quite similar to the yellow-legged frog. I expect you saw a Columbia spotted frog at Long Lake. If you are interested, we have some web content that is still being developed and therefore not yet linked to the IDFG webpage that will allow you to see a list of the amphibians that do occur in the state. We have photographs of some of these, including the Columbia spotted frog. If you are interested, go to this link https://fishandgame.idaho.gov/species/taxa and choose "Amphibians" from the drop-down list under the Category box. This should filter a list of all of our amphibians. I apologize that this content is not fully developed, but it will give you some accurate species lists at this time.