CHICAGO—Chicago Park District Supt. Tim Mitchell defended his record during an interview three months ago. But tonight, the district’s board released a statement saying after seven years at the helm of one of the nation’s largest park systems, Mitchell will resign next month.

Last week, Mitchell’s chief of staff, Shawn Schmidt, also left his job — after FOX Chicago News and the Better Government Association raised questions about charges posted to Schmidt’s Park District credit card.

The BGA’s Andy Shaw says our joint investigations put the heat on the Park District board.

“It took a long time for this Park Board to understand they had a problem,” Shaw explained. “I think the Emanuel administration reminded them of that problem and now it looks like they’re doing the right thing.”

We found Mitchell and Schmidt charging taxpayers for airline upgrades into roomier seats, meals on the road at expensive restaurants and stays at luxury hotels.

Earlier stories uncovered other Park District problems, including the hiring of a top manager who had just been fired by the city for crashing his city-leased car while drunk, and a contract awarded to a fitness instructor who just happened to be living with the Park District supervisor who signed off on the deal.

A source close to the situation says all those stories helped speed Mitchell’s departure.

“I think it’s safe to say there will be a lot of new faces, hopefully people who understand accountability and transparency a little bit better, and presumably an operation that spends its money on better parks, not better perks,” Shaw said.

In its statement, the board thanks Mitchell for “great dedication and vision. During his tenure the (District) has acquired more than 1,000 acres of new parkland, and improved parks throughout Chicago.”

Former Ald. Mary Ann Smith, who chaired the City Council Parks Committee, also praises Mitchell’s stewardship, but says the next superintendent faces some tough challenges.

“Everyone has to do more with less,” Smith said. “I would say we need more public-private partnerships. We need more underwriting, more sponsorships. We need more parent participation.”

TIMELINE OF BGA/FOX CHICAGO INVESTIGATIONS

DEC. 21, 2010 Chicago Park District Supervisor Resigns After Questionable Contract	JAN. 14, 2011 Clout Trumps Consequences: New Job for Insider Despite DUI, Cover-Up	MAY 5, 2011 Taxpayers Shouldered Chicago Park District Chief of Staff’s Credit Card Charges	MAY 20, 2011 Floored: Park District Slow to Repair Vital West Side Gymnasium	JUNE 1, 2011 BGA Investigations Prompt Early Exit for Parks Chief