Some of harness racing's top trainers and drivers, who will compete for an estimated $7.5 million in total purses, will be featured in Freestate Raceway's 115-night summer meet, which opens tonight.

The meet runs through Oct. 4 with racing six nights a week, Tuesday through Sunday. Starting in September, Tuesday nights also will be dark. Post time is 7:30 nightly, except on Sundays and holidays when it will be 6 p.m. Freestate also will race on Memorial Day Monday.

Freestate's major events for 2-year-old pacers again will be the Potomac for colts on July 5, which carries an estimated purse of $500,000, and the Lady Baltimore for fillies on Sept. 6 for $425,000.

Freestate will have two top events for 3-year-old pacers. The $300,000 Terrapin for colts is on June 7 and the $200,000 Turtle Dove for fillies is on Aug. 9.

Barberry Spur, 1985's 2-year-old colt of the year, and Cash Asset, winner of the Miller Memorial at Rosecroft this month, will be racing at Freestate the first three Saturdays of the meet in preparation for the Terrapin.

Freestate also will play host to the Grand Circuit for a week starting June 1. One of the oldest traditions in sports, the Grand Circuit was begun in 1871 and is a traveling tour of some of harness racing's top horses and horsemen. Freestate, which will offer four 3-year-old stake races during the week, is the second stop on the 18-track Grand Circuit tour this season.

Stabled at Freestate are top horsemen Jim Crane, Ron Waples and Jim Miller. Returning to Freestate after a successful season at the track last year are Abe Stoltzfus, Lofty Bruce and Ted Wing.

Rosecroft at Ocean City, the temporary new name for Ocean Downs, in which Rosecroft Raceway purchased a controlling interest six weeks ago, begins its first meet Friday.