My wife and I were walking up to Cecret Lake, at 10,000 ft. in Little Cottonwood Canyon, above Salt Lake City. When we got there, I said, "Oh fish!" Iris pointed out that they had too many dangley bits, and I took a closer look. "Tadpoles!" I said, but then I remembered that tadpoles don't have external gills along the back of the head like that. So I eventually figured out they must be salamander larvae. But what salamader has 6 inch long larvae? The tiger salamander, Ambystoma tigrinum.
This struck us as particularly fortuitous, as we only a month ago named a kitten Tigrinum, in honor of this species. Quite a resemblance, wouldn't you say?
Tiger salamanders often breed in mountain lakes and streams, and their populations often die out when fish are introduced to their previously fishless breeding grounds. Those big slow larvae are easy prey for predatory fish.