Dust and sand heaped up against fence windbreak. "Local drifting began almost
imperceptibly and finally merged with regional blowing."Prior to the 1930's
there had been a number of episodes of dust storms occurring in the Dust Bowl
area. In: "Erosion and Its Control in Oklahoma Territory," Angus H. McDonald,
Misc. Publication No. 301, Department of Agriculture. 1938. Figure 2. S21.A46.