[1] Its county seat is Crookston,[2] and the largest community is East Grand Forks.

Polk County is part of the Grand Forks, ND-MN metropolitan statistical area.

In one of its early acts as a state entity, the Minnesota Legislature created the county on July 20, 1858, but did not organize it at that time.

The county was named for the 11th president of the United States, James Knox Polk, who signed the congressional act that organized the Minnesota Territory.

[3] Polk County lies on Minnesota's border with North Dakota (across the Red River).

The county terrain consists of low, rolling hills, devoted to agriculture.

[4] The county slopes to the west and north, with its highest point near its southeast corner, at 1,519 ft (463 m) above sea level.

There were 14,623 housing units at an average density of 7.42 inhabitants per square mile (2.9/km2).

There were 14,610 housing units at an average density of 7.41 inhabitants per square mile (2.9/km2).

There were 14,008 housing units at an average density of 7.11 inhabitants per square mile (2.7/km2).