The hills are described by Upham as "running southeast from Fergus Falls to the south line of the county and thence east and northeast to East Leaf Lake, a distance of 50 miles." Through their full extent in Otter Tail County, the hills have steeply sloped sides covered by prairies and deciduous forests, primarily maple and oak. In most regions these hills would not be considered mountains, but in generally flat Minnesota they are significant and unique features of the landscape, much more notable than in a really mountainous area.