Rosecroft Raceway in Oxon Hill will open the earliest harness-racing season in Maryland history tonight, with an 8 o'clock post time for the first of 10 races.

The track's 85-night meeting runs through June 6, with action then shifting to Freestate Raceway in Laurel.

As usual, the highlight of the Rosecroft meeting will be the William E. Miller Memorial Pace, named afterthe track's founder. This year's open race for 3-year-olds May 9 is expected to have an $85,000 purse.

Tonight's opening card features five divisions of the Representative Pace, a late-closing series that will be contested each Thursday night for five weeks, with a $7,500 final scheduled Saturday, April 4. One of the favorites in the series will be Convoy, trained and driven by Ralph Hollway.

Most of the top drivers who regularly compete on the Maryland circuit are back, including Wayne Smullin, Walter Callahan, Bobby Myers, Jim Brittingham and Vic White. Bib Roberts, another top driver, will send part of his stable here but will remain in Florida for a while with his top colts.

Some familiar names among the horses also will be back on the cards. Come On Fred, who has become a local crowd favorite, is entered in Saturday night's feature.

Racing secretary Billy Perkins said that he has no shortage of horses, with 1,341 applications for the 730 available stalls on the grounds.