Zion's Navajo Sandstone began as desert dunes; streams later cut the canyon through those thick layers. Water moves through the sandstone and along the less-permeable Kayenta layer, then seeps out at canyon walls. That's the broader geology behind Zion's springs and cliffside water, though no single source was identified for each pool. Flow here changes with rain and snowmelt.
The pools are fragile and an important water source for wildlife. Swimming and entering the pools are prohibited. Stay on the path and back from the cliff edges.