| One of 12 thinning densities established on the Black Hills Experimental Forest in 1962. They were followed through 2010 when the trees in the study were killed by mountain pine beetles.
||Snapshot : Throughout the Rocky Mountains over the last century, large ponderosa pine trees provided lumber for growing cities and towns, along with fuel and timber for the mining and railroad industries. Most of these forests are now occupied by dense, young, and mid-aged forests highly susceptible to mortality from bark beetle infestation and wildfire. These conditions are exacerbated by fire suppression and urban encroachment. As a result, land managers need knowledge to inform management actions directed at restoring and conserving ponderosa pine forests.