The shield volcano is topped by a volcanic crater. While the crater rim is free of snow and ice, snow tends to linger on the summit well into July. A small crater lake by the name of Lake Wapiki, occupies the crater below the Lemei Rock high point. The Lost and Dry Creeks flow off of the southeast side of Lemei Rock and join the White Salmon River, while the Smokey, Little Goose, and Cultus flow from the east and northeast side, and joins Trout Lake Creek, which then discharges into the White Salmon River at Trout Lake. The Rush Creek flows from the west side of Lemei Rock and joins the Lewis River between the Lower Lewis River Falls Recreation Area and the Swift Reservoir.