Observation Rock is an apt name for this remnant vent on the north side of Rainier, about 4 miles NNW of Rainier's summit crater. Understandably, Ob Rock's summit provides unmatched views of the north faces and glaciers of Rainier. Even with its friable nature, Ob Rock is a popular objective. It even boasts a beginner ice climb on a north-facing ice sheet. The peak presides over Spray Park and is an easy to moderate scramble from there. The peak can be climbed in a day from the Mowich Lake trailhead. Ice axes and crampons are needed later in the season on some of the icefields around its base (this is the Flett Glacier). Some crevasses exist but these are mostly avoidable