Hosted by the Essex County Velo Cycling Club, the event opens the Shimano New England Pro Cyclocross Series, which offers more than $50,000 in prize money and will also make stops in Northampton, Providence, and Warwick, R.I.

Often called the steeplechase of cycling, cyclocross is a mix of road racing, mountain biking, and running on an obstacle course. It requires jostling for position while negotiating sharp turns, mud, sand, hills, and hurdles. Races begin Saturday and Sunday at 8 a.m. and continue through the day.

Visit www.gpgloucester.com for more details.