Kelly Warm Spring is a geothermally fed pond that maintains tropical temperatures year round even in the middle of winter.in this alpine environment. I took my snorkel cam and decided to go for a dip in the pleasantly tepid water in the spring only to discover tropical fish swimming in the pond.These lucky underwater denizens enjoy the heated waters year round and were probably dumped her by aquarists who abandoned their pet fish when they left Teton Village or Jackson Hole when the ski season ended. Stop by and bring some fish food! see: http://www.rei.com/guidepost/detail/wyoming/hot-springs/kelly-warm-springs/21550