My daughter Rori is studying Public Health at CU Boulder, and like every student there she walks alongside Boulder Creek on her way to class. It's a beautiful, fast-moving creek — especially in spring — and one day she asked me where all that water comes from. I didn't know the full answer. So I built her this map.
Turns out, Boulder Creek has one of the most remarkable origin stories of any urban waterway in America. The water flowing past the CU campus started as snow on the Continental Divide, just 25 miles to the west. Some of it melted off the Arapaho Glacier — the southernmost glacier in the contiguous United States. It collected in high alpine lakes above 11,000 feet, dripped through billion-year-old granite in a dramatic canyon, and pooled behind a dam built in 1910 before finally making its way through town.
The interactive map below traces the full journey. Click any marker to learn about each water source — from the glacier and snowfields of the Indian Peaks Wilderness to Barker Reservoir in Nederland to the creek path right through campus. You can also switch to satellite view for a stunning aerial perspective of the terrain.
I described what I wanted to Cowork — "an interactive website showing where the water comes from that ends up in Boulder Creek, for my daughter Rori at CU" — and it built the whole thing. The map uses Leaflet.js with ESRI topographic tiles, a hand-drawn watershed polygon, and animated flow paths. Scroll down and explore.