The Forest Service burned to get some good PR and hired a firm to create a misleading brochure for them. In the brochure 6 small B&W photos spanning 80 years are shown
"The 1909 photo shows an open, parklike forest with large trees spaced widely apart. More trees and underbrush appear in each successive picture -- 1948, 1958, 1968, 1979 -- and finally a photo thick with trees in 1989.
"Today's forests, dense with green, may seem beautiful, but in fact are deadly,' the pamphlet reads. 'Our old-growth forests are choking with brush, tinder-dry debris, and dead trees which make the risk of catastrophic fire high."'
However, the 1909 photo picture does not show a forest natural conditions -- it was taken just after the forest had logged. Also, the forest pictured isn't in Sierra Nevada. It is in Montana.