Mosca Pass and Medano Creek

I’d passed through Great Sand Dunes National Park two summers ago on my way back from Utah, but hadn’t spent much time there. This time, I hiked the Mosca Pass Trail, a gap in the mountains that is one component of a complex set of interrelationships maintaining the dunes.

The components include erosion (sand) from the San Juan Mountains, which gets blown across the valley floor until it is scooped up by the Sangre de Christo Mountains, rising up behind the dunes, and sculpted by runoff from mountain snowpack and wind channeled between mountain passes on either side.

Mosca Pass, the more southern of these two passes, features a trail running tightly along the mountainside then through open meadows accented by aspen groves, explosions of brilliant, rustling, lime green. Finally, the trail finds the ridge, unveiling the other side: rolling valley then more mountains. Pure Colorado.

After the hike, I visited Medano Creek. The the chilly, gurgling water which not long ago was snow only runs in spring. It wasn’t flowing when I visited previously in July.