Most North Dakotans are well aware of the rich soils of the Red River Valley, what was once glacial Lake Agassiz. Although less well known, glacial Lake Souris also has rich soils.
It covered much of Bottineau and McHenry counties as well as portions of Rolette and Pierce counties. These lakebeds are characterized by a level landscape with rich soils, so it may come as a surprise the glacial Lake Souris is associated with large areas of sandy soils and sand dunes.
Glacial Lake Souris formed in front of the receding glacier at the end of the last ice age. The lake lasted for several thousand years, and as one might expect, it changed in size and elevation during its existence. It is interesting to note that glacial Lake Regina in southeastern Saskatchewan released a torrent of water at the end of the ice age that cut both the Souris and Des Lacs River valleys. Glacial Lake Souris has drained, of course, with the Souris River now draining much of this region.
Some of the sandy areas associated with glacial Lake Souris include that along Highway 60 from near Willow City to where it heads eastward to meet Highway 3. It is also noticeable along Highway 14 from around Upham to Towner, and is quite conspicuous around Denbigh and to the northwest. Travelers will also notice the sandy soils several miles south of Towner along Highway 14 around halfway to the intersection with Highway 52 west of Anamoose.
These sandy areas originated from near-shore and off-shore locations of glacial Lake Souris. Areas of sand dunes associated with the lake are particularly evident around Towner, Bantry, and Denbigh. The dunes in the Denbigh area, for example, can reach heights of over fifty feet and support some rather unique sand prairie.
If you are interested in taking a closer look at these sandy areas and the plants and animals that call these areas home, consider taking a trip to J. Clark Salyer National Wildlife Refuge near Upham. The refuge has auto tour routes and a sandhills walk area. The sand dunes, in particular, support an interesting mix of plants, including prairie sandreed, sand bluestem, sand dropseed, and cactus. There are also scattered stands of bur oak and quaking aspen.
