Kachina Bridge was named for the Hopi kachina spirits, which frequently displayed lightning snake symbols on their bodies. Similar snake patterns were carved by prehistoric people on the base of Kachina Bridge. It is the best place in the monument to observe the making of a natural bridge. Here, meandering streams cut downward into the Cedar Mesa Sandstone, leaving a thin wall of rock. The streams attacked the wall from both sides, eroding the weaker areas. Eventually, the streams broke through the wall, creating a natural bridge. Kachina Bridge is still being enlarged by the streams, as flash floods wear away at the abutments and gravity pulls at loose rocks.