Starting in the summer of 1928, FC Gates led systematic measurements of forest vegetation with the Plant Ecology class until 1954. Some of the measurements were taken in randomly located quadrants within specific stands and taken in the same area each summer. These stands included sets of aspen, pine, hardwoods, cedar stands, and bogs, most of which had been disturbed at different times since the 19th century (In "Changes in the vegetation and population of aspens"). The Aspen Associations were sampled regularly during this period to gain an understanding of succession after fire. Dr. Gates left no permanent record of the 10 aspen sets. Of the 10 plots, Sets 1-4 have been located and mapped (Thompson 1978). They include two stands that burned after fires were inadvertently started in 1901, 1911 and 1923. The 1936 burn is included as "Aspen Set 4". Students collected quadrat counts within these stands each summer through 1954 with Frank Gates (Method described below). Later resampling occurred by Arthur Cooper, James Teeri, Sam Scheiner, and others.