A settlement began at the future city of Wadena in 1871,[2] and by 1873 a post office was in operation there.

The town took the name of a trading post 15 miles (24 km) to the east, which had flourished for several years but was largely abandoned by that time.

Each township is six miles square and contains 36 sections of land (with the exception of Bullard and Thomastown, which have a slightly different configuration because their boundaries are aligned with the Leaf and Crow Wing Rivers, respectively).

In 1857 Augustus Aspinwall laid out a town site in what is now Section 15, Thomastown township, at the junction of the Crow Wing and Partridge rivers, and named it Wadena.

When the railroad went through the area in 1872, it ran about three miles south of this site and the town quickly withered away.

The Northern Pacific main line running east to west through Wadena was built in 1872, while the Great Northern branch or "K" line which ran from Sauk Centre to Bemidji, via Sebeka and Menahga, was completed in 1891.

In 2010 there were four organized school districts in the county: Wadena, Verndale, Sebeka and Menahga.

The county terrain consists of low rolling hills, carved by drainages, devoted to agriculture wherever possible.

[6] The terrain slopes to the east and south, with its highest point near its northwest corner, at 1,460 ft (450 m) ASL.