What was this marvelous occurrence? Why, I'm glad you asked. I hiked up to a little place called Lake Blanche, in Big Cottonwood Canyon in the Wasatch range east of Salt Lake City. It's only about 20 minutes away, but it's worth driving hours for. Along with Lake Blanche, there are two other alpine lakes: Lake Florence and Lake Lillian. Blanche flows into Florence (via a nice stretch of white water), which flows into Lillian, which flows as a whitewater brook down a valley into the canyon. The lakes appear to be natural, but have been preserved with earthen dams, ostensibly to raise the water level. There's still some snow left in higher elevations, especially on north-facing slopes, so the creeks are running really high right now, and there's waterfalls absolutely everywhere
And now for some pictures of the lakes themselves, starting with Lake Blanche:
Lake Florence (with the connecting waterfall from Lake Blanche in the background):
Lakes Florence (foreground) and Lillian (background):
Short sleeves and tan arms with a... snowball?
Welcome to Switzerland!
All in all, one of the best hikes I've ever done.