LAS VEGAS (KLAS) — With monsoon storms popping up all over southern Nevada Monday, a sight that is unlike anything most have seen appeared near the Hoover Dam.

Several large waterfalls could be seen on the Black Canyon walls Monday afternoon. The largest one was seen just south of the Nevada generator powerhouse.

According to the Bureau of Reclamation’s Hoover Dam Facebook page, the waterfalls were from flash flooding in the surrounding slot canyons.

The Bureau also reminded people to “remember that flash floods are dangerous and can be deadly. Never try to outswim a flood and check the weather before entering a slot canyon.”