Oregon State Archives posted an historic photo of Mirror Lake on their Facebook page yesterday.
Undated photo of Mirror Lake (Oregon State Archives)
I thought at first that the denuded forest was the result of logging, but it might be because of a wildfire. A fire did hit the area in April of 1931. In the April 28, 1931 edition of The Oregonian, there were several separate mentions of a fire at Mirror Lake and at nearby Laurel Hill during an unusual spring heat wave:
Whether before or after that fire (most likely before), this area was definitely heavily logged, and in fact if you hike up to Mirror Lake you can see huge stumps with the springboard notches in them.
Springboard logging on Larch Mountain in 1943 (USFS)
Old springboard notches along the Mirror Lake Trail in 2013
Mirror Lake has been a popular hiking destination for many years. The following write-up appeared in the March 11, 1934 edition of The Oregonian.
Today Mirror Lake is one of the most popular hiking destinations in the Mt. Hood National Forest. The view has changed somewhat from the old postcard above since the trees have grown up quite a bit.
Mirror Lake in 2006