Cerro La Jara Stop 3

Alluvial fans at the base of Valles Caldera's south rim.

NPS

Look to your left, across the road to the mountains in the distance. There are deposits of rocks and sand at the base of the mountains. These deposits are called alluvial fans. Alluvial fans get their name from their shape and what they are made of. Rocks, sand, and silt moved and deposited by running water is called alluvium. Alluvial fans are fan-shaped deposits of alluvium. Water flowing downhill out of the mountains moves the sediment downhill and deposits it in the valley.

Continue down the path to Stop 4, where you'll observe a large boulder on the left side of the trail.