")[citation needed] During the summer, Chehalis Lake is a popular location for camping, recreational fishing, and hiking.

[3] On December 4, 2007, a rockslide with a volume of 3,000,000 cubic metres (3,900,000 cu yd) slid down the side of 1,563-metre (5,128 ft) high Mount Orrock on an east-facing slope.

[1][2][3] It destroyed a 400-metre (440 yd) section of a forest service road and about 25 hectares (62 acres) of commercially marketable timber.

[2] The wave was 6.3 metres (21 ft) tall at the lake's exit point, 7.5 kilometres (4.7 mi) away to the south.

[1][2] The event occurred during the winter when cold weather deters visits to the lake, so there were no eyewitnesses to it or deaths or injuries resulting from it.