In the eastern part are several creeks, the largest of which is Willow, which rises in the Sweet Grass Hills and follows a southerly course through the county.

In the Sweet Grass Hills and elsewhere indications of oil and gas have been found.

[citation needed] As of the 2010 census, there were 5,324 people, 2,015 households, and 1,246 families in the county.

In terms of ancestry, 30.8% were German, 17.7% were Irish, 15.8% were English, 10.5% were Norwegian, and 3.6% were American.

Toole County voters have only selected Republican Party candidates in national elections since 1964.