Pinnacle Peak is one of several small volcanoes in the Enumclaw area. Since we live in a high rainfall area, the rock mountain is covered with trees and other vegetation. A few thousand years ago, Mt Rainier experienced a cataclysmic eruption, triggering the Oceola mudflow. The resulting lake of mud left the peaks of these volcanoes as islands, rising abruptly from the flat surface.

On the north side, a challenging trail takes you from the Plateau up 1000 feet in only one mile. A steep road climbs the south side is closed to motorized vehicles, but open to mountain bikers and recumbent trikers who have high enough stamina and low enough gears.