From web site at URL http://www.firelookout.com/wa/slate.html

SLATE PEAK LOOKOUT
16 miles northwest of Mazama WA
Okanogan National Forest
7440`

Slate Peak borders the Pasayten Wilderness Area in Washington`s North Cascades. The first lookout structure here was a 1924 gable-roof cupola cabin. The current 41` treated timber tower with L-4 cab was built in 1956, after the Air Force decided they didn`t need to build a radar station here. The summit was formerly 40` higher, but the Air Force kicked out the U.S. Forest Service tenant, destroyed the L-4 cabin which had been moved to the summit just 2 years earlier from Leecher Mtn. Lookout, and blasted the top 40` off the mountain. The project was declared obsolete before completion, and what remains is a huge flat summit. It is the highest point in Washington accessible by automobile. The lookout was pressed into emergency service during 1994 when nearby Goat Peak Lookout had to be evacuated because of a forest fire. It was used in 1996 to monitor the Elbow Basin fire in the Pasayten Wilderness, and relay radio messages from personnel on the fire. Photo © Rex Kamstra.