Four Experimental Forests were pivotal in piloting the long-term soil productivity (LTSP) cooperative research program - one of the most successful and extensive collaborative science efforts yet undertaken by the USDA Forest Service. Launched on the Palustris, Challenge, Marcell, and Priest River Experimental Forests, LTSP traces to a seminal discussion during a field tour in central Louisiana in 1986. P. E. Avers, National Soils Program Leader in Washington DC, described to D. H. Alban and R. F. Powers a problem arising from the National Forest Management Act of 1976 (NFMA). That conversation sparked an idea that quickly caught fire. This chapter documents how LTSP came to be and why four Experimental Forests were central to its success. It began with a ripple effect of the NFMA.