Polk County was established in 1858. Polk County included nearly the entire northwestern corner of Minnesota, representing the present counties of Polk, Norman, Red Lake and Pennington, and parts of Beltrami, Clay, Becker and Hubbard Counties. Its total area covered over 7,000 miles.

Gradually legislation diminished the size of the county until nothing remained but the territory now comprising Polk, Red Lake and Pennington Counties. It was still large, in fact ranking fourth in size among all counties in the state.

A 10-year battle had developed to separate Polk and Red Lake into independent counties. The main reason for the battle, as expressed by supporters of a new Red Lake county, was that Crookston, being the county seat of Polk drew all the strength of the county to itself, but rarely did anything of service for the people. Outlying towns and farming districts were scarcely recognized except for the payment of taxes.

In the 1896 election three new counties were formed from within Polk, after receiving the necessary votes to become independent. However, the boundaries of Red Lake, Mills and Columbia Counties overlapped and each had a different designated county seat. After a diligent fight in St. Paul by several Red Lake Falls residents, Red Lake was duly declared a county by Gov. David M. Clough on Christmas Eve, 1896. In the proposition to create Red Lake County, five men had been named as its first board of commissioners. These men traveled to Crookston, arriving at 3 a.m., Dec. 26, at the office of the clerk of court and filed certified copies of the governor's proclamation with the commissioners' oaths of office endorsed on the back.

For more, see article by Charles Boughton: http://nmin.ardc.org/history/rlsep.asp

Soon after Red Lake was officially declared a county, the residents of Thief River Falls began a campaign to name their city as the county seat. The law prohibited a change in the county seat for five years, yet this campaign prevented the construction of a decent courthouse.

Finally, in April of 1905, a petition with 2,006 signatures was presented at the county auditor's office by officials from Thief River Falls in an effort to move the seat to their county. Lawsuit after lawsuit was tried as Red Lake Falls officials attacked the legality of the petition. This battle lasted five years until suspected arson finally brought the matter to a head.

On April 23, 1909 the county courthouse was completely destroyed by a mysterious fire. It was rumored that the local fire brigade arrived suspiciously late and records show members of the brigade joked about the incident at the scene of the fire, winking at each other and commenting on how the blaze could have started. The fire was blamed on a defective chimney and temporary offices were set up in the Healy Land Co. building also in Red Lake Falls.

Plans for a new courthouse were drawn and a resolution for the sale of bonds to raise money for construction was passed. In an attempt to prevent construction but the case was lost.

While the courthouse in Red Lake Falls was under construction the Red Lake County was severed by the Minnesota legislature creating Pennington County and Thief River Falls was named the county seat. Shortly after this the Minnesota Supreme Court ruled that Pennington County residents would have to help pay for the Red Lake County courthouse since the bond issue, which had been passed by the Red Lake County Commissioners was still legally binding on the residents of Pennington County since they had been Red Lake residents at the time the issue was passed. The cornerstone was laid on June 11, 1910 and construction was completed by early February, 1911.