Mount Margaret Lookout Camp
This source is from the 1920 Directory Of National Forests In Washington. This paragraph lists 7 lookout camps. None of these sites had structures in early 1920. Six of them are well known locations, while this is the first reference to Mount Margaret I have ever seen.
Tumwater Mountain was a camp in 1914 lasting to around 1923
Dirtyface Peak was a camp in 1914, structure built in 1920
Sugarloaf Peak was a camp in 1914, structure built in 1924
Tiptop was a camp in 1914, structure built in 1925
Red Top was a camp in 1918, structure built in 1924
Jolly Mountain was a camp in 1916, structure built in 1921
Mount Margaret (this reveals it was a camp in 1920)
Washington Lookout Sites
More to come:
I've snowshoed up but will return when I have more information about where the camp was located.