Denbigh Experimental Forest in north-central North Dakota was established in 1931 as a working test site on the northern Great Plains, where damaged, over-plowed, and overgrazed land became a place to determine which shelterbelt trees, seed sources, and planting methods could succeed. Created amid broader shelterbelt efforts during the Great Depression, it never became the vast forest once envisioned, but instead developed into a focused experimental arboretum. More than 40 species were planted, with about 30 woody species surviving. Though research has ended, the site has continued producing about 500,000 seedlings annually for wind protection in the United States and Canada and is being returned to Custer National Forest control.