Hillary Rodham Clinton's embattled presidential campaign showed signs Wednesday that it isn't giving up in the Upper Midwest without a fight.

Clinton was scheduled to campaign today in South Dakota, where Democrats will hold their presidential primary on June 3, the final day of Democratic contests.

And former President Bill Clinton is returning to the Twin Cities on May 22 to raise money for his wife's campaign. The announcement of the fundraiser came the same day her campaign confirmed she had lent it $6.4 million.

Details of the former president's fundraiser have not been finalized, but donors will be asked to contribute a minimum of $25, according to Hubert (Buck) Humphrey IV, Hillary Clinton's Minnesota campaign manager.

Hillary Clinton planned an airport rally in Sioux Falls at Joe Foss Field, the candidate's South Dakota web page reports. The one-hour event was to start at 2:15 p.m.

South Dakota now finds itself in an unusual position politically, with the potential for more relevance as the nomination battle between Clinton and rival Barack Obama marches on. There are 23 delegates at stake in South Dakota.

Montana holds the other final Democratic primary on June 3.

On Monday in Sioux Falls, the Clinton campaign opened its state headquarters at the Western Mall. An open house attracted more than 200 supporters, the state campaign said.

BOB VON STERNBERG