<p>Afforestation and reforestation efforts are being utilized throughout the United States; however, historical tree planting efforts, such as the Clarke–McNary Act, have not yet encompassed broader quantitative evaluation in terms of types of trees planted, number of trees planted, and percent success of plantings. The Clarke–McNary Act was passed on June 7, 1924 to facilitate more cognizant partnerships for tree planting from private landowners and public forestry initiatives with federal and state cooperation. The purpose of this research is to understand the historical aspects of the Clarke–McNary tree planting program, alongside more recent eDNA technology to better understand species assemblages in afforested and reforested areas in the Black Hills, South Dakota. The results of this research reflected that elm, ash (<i>Fraxinus lanceolata</i>), honey locust (<i>Gleditsia inermis</i>), black locust (<i>Robinia pseudoacacia</i>), and Douglas fir (<i>Pseudotsuga taxifolia</i>) trees were the more commonly afforested species, while jack pine (<i>Pinus banksiana</i>) and ponderosa pine (<i>Pinus ponderosa</i>) were more common reforested species. This research also found that afforestation efforts were significantly (<i>p</i> &lt; 0.001) more successful than reforestation efforts under the Clarke–McNary Act and there was no significant difference in the number of acres planted between afforested and reforested areas. eDNA metabarcoding on ponderosa pine needles revealed a mixture of bacterial, fungal, and higher-order species assemblages identified on Clarke–McNary reforested and non-Clarke–McNary afforested sites. As afforestation and reforestation efforts continue to occur via tree planting programs, such as the Clarke–McNary Act, it will be important to quantify the benefits that these historical and future programs provide for conservation initiatives in the United States.</p>