MILWAUKEE (AP) — The Milwaukee Mile’s past includes more than a century’s worth of auto racing’s biggest names, from A.J. Foyt to the Unsers and the Andrettis. Now the track’s promoters are behind on payments to NASCAR and the Indy Racing League, leaving its future uncertain.

The Milwaukee Mile hosted its two biggest events of the year over the past month: An IndyCar series race May 31 and NASCAR’s Nationwide and Camping World Trucks series races June 20. While the IndyCar and Nationwide dates drew decent crowds, the track’s promoters still are struggling to meet their financial obligations.

Promoters have paid prize money to teams but they have not fully paid sanctioning fees owed to NASCAR and the IRL, according to reports in the Charlotte Observer and Indianapolis Star. Both leagues confirmed those reports to The Associated Press on Tuesday.

“Despite having a terrific day of NASCAR racing, there remain outstanding issues which concern NASCAR,” NASCAR spokesman Ramsey Poston said. “As a matter of policy, I won’t get into the specifics of our business dealings, however, I can say we are working closely with the track management to resolve outstanding issues.”

IRL spokesman John Griffin acknowledged the league’s issue with the Milwaukee promoter, and said league officials are trying to set up a meeting to work things out. Until they do, the track’s date on next year’s schedule is in limbo.

“We’ve really got to clear up these outstanding issues from 2009 before we look at 2010,” Griffin said.

Wisconsin Motorsports was announced as the track’s new promoter in February, replacing Milwaukee Mile Holdings LLC. The track trumpeted the move as one that “ensures the near-term and long-term future of auto racing at America’s Legendary Oval.”

Yet the Milwaukee Journal Sentinel has reported that promoters owe NASCAR nearly $1.9 million. A track spokesman said officials had no comment beyond what Claude Napier, president and CEO of Wisconsin Motorsports, told the Journal Sentinel over the weekend: That some advance ticket revenue for this year’s races was collected by Milwaukee Mile Holdings.

Napier also told the paper that NASCAR’s decision to clamp down on racing teams’ midweek test sessions has hurt financially.

Unless the promoters can pull a quick turnaround, a significant piece of U.S. auto racing history will be at risk.

Located at the state fairgrounds in a residential neighborhood just west of downtown Milwaukee, the track bills itself as the oldest active auto racing facility in the country, hosting its first race in 1903 — eight years before the first Indianapolis 500.

The track’s list of open-wheel race winners reads like a racing Hall of Fame: Foyt, Roger Ward, Jimmy Clark, Parnelli Jones, Mario and Michael Andretti, Al Unser Sr., Al Unser Jr. and Bobby Unser, Tom Sneva and Rick Mears. NASCAR races are a more recent addition to the track, but have proven to be popular.

And the track’s legacy extends beyond racing. It hosted some Green Bay Packers games on its infield during the 1930s — including the 1939 NFL championship game, in which the Packers beat the New York Giants 27-0.

While neither NASCAR nor the IRL has publicly set a deadline for payment or threatened legal action, important deadlines loom. Both series are expected to issue next year’s racing schedule later this year — and if the Milwaukee Mile isn’t on those schedules, it could be the beginning of the end for the venerable track.