GROTON — Downtown Mystic motorists should plan for temporary road closures Saturday, November 7, as runners take part in the 51st Tarzan Brown Mystic River Run.

Town of Groton Police announced an advisory window of 8:30 a.m. to 12:30 p.m. for the race, sponsored by the Greater Mystic Chamber of Commerce.

Pearl Street will close between Clift Street and West Main Street at 8:30 a.m. and remain closed until the race ends, police said.

Clift Street, Grove Avenue, Starr Street and Gravel Street will have brief closures at 9:20 a.m. for the children’s run and again just before the adult race begins at 10 a.m.

River Road will close just before the adult race starts at 10 a.m. and reopen when safety permits, according to the department.

Police asked drivers, runners and spectators to remain alert when traveling through downtown Mystic during the event.