About 25 protesters who want the annual summertime Belle Isle Grand Prix auto race to leave the state-run island park east of downtown Detroit picketed along Jefferson Avenue Saturday, the Detroit Free Press reports.

"Picnics not pitstops" and "stop corporate greed" were among the slogans on their signs.

Since the Belle Isle Grand Prix was revived consistently on the island in 2012 -- the course ran through downtown in the 1980s -- the Belle Isle Conservancy has become increasingly dependent on the fees and fundraising generated from the event.

In 2015 the Belle Isle Grand Prix paid $200,000 and helped raise $1.1 million for the Belle Isle Conservancy through its Grand Prixmiere charity event. With the help of sponsors, the race reopened and operates the Scott Fountain, added LED lights to the MacArthur Bridge, installed walkways and benches and made other island improvements.

In exchange, race organizers are allowed shut down a western section of the island, where the Casino and Scott Fountain are located, for a large chunk of the summer leading up to and after the event.

Portions of grass at Belle Isle and nearby Erma Henderson Park were destroyed last year, turned to mud by heavy rains and parking.

Grand Prix organizers incurred the cost of repairs.

To the disdain of some, the island agreed to allow another auto race, the Red Bull Rally Cross, use a section of the island last July.

Nearly 100 people attended a Belle Isle Advisory Committee meeting to oppose the decision. The race paid the Belle Isle Conservancy $25,000 for the weekend event.

It's not scheduled to return this summer.

It's estimated the annual Detroit Belle Isle Grand Prix draws over 100,000 attendees and the Friday of race weekend, when time trials are held, are free to the public.

This year's race takes place June 3 through June 5.

The 1976-formed New Wave band the Romantics from Detroit are performing Saturday at the Grand Prix.