Mosaic Canyon - Death Valley NP

Why was water here? Glaciers? Yearly flood?

Why its called Mosaic Canyon. The walls were composed of two very different materials, a water smoothed slab of something hard like granite, and a second layer which was very much like unsmoothed concrete. Jagged edges sticking up all over the place.

The two different materials interfacing.


Why was there sooo much water here?