Downtown Rockland will be throwing a big party Saturday, June 21, from 4 to 8 p.m. complete with music, food and retail vendors.

The Annual Summer Solstice Celebration is produced by Rockland Main Street, Inc., and sponsored by Camden National Bank.

The decades-long tradition for families from all across the Midcoast region will bring up to 5,000 people to a Main Street that will be closed to vehicular traffic for four hours. During that time, the street will be filled with pedestrians enjoying various bands, plenty of food, and fun for all ages.

One of the big attractions will be the traditional Whoopie Pie-Eating Contest, sponsored by Rockland Café, where registration begins at 4 p.m. and the contest begins at 6 p.m.

In addition to live music and food, festivities will include games and prizes for children, dancing, and a spontaneous flash mob dance where everyone is encouraged to participate. Free public dance instructions led by Dancing Elephant will be available from 7 a.m. to 4 p.m. on the waterfront.

Free face painting, temporary tattoos, giant bubbles, art classes, knitting classes, and a street chalk-art exhibition are also scheduled.

While this is a free, family event, members of the Rock Coast Rollers roller-derby team will collect donations to support Rockland Main Street, Inc., events in between skating demonstrations.

Some of the non-profit organizations anticipated to be on hand will be Pope Memorial Humane Society of Knox County, the Kiwanis Club of Rockland, the Maine Lobster Festival, and the Farnsworth Art Museum.

Many retail and service businesses will be open and all of the restaurants are expected to be open for dinner.

During this rain-or-shine event, organizers have said that smoking on Main Street will be prohibited. Dogs are encouraged to keep their humans on a short leash throughout the evening. Those humans are expected to demonstrate courtesy to others by ensuring that their pets do not leave anything behind.

According to Gordon Page, executive director of Rockland Main Street, Inc., Main Street will be closed to vehicular traffic from the corner of Park Street all the way to Summer Street, but the entire harbor will be accessible to vehicles via Park Drive and the Harbor Park entrance next to Mildred Merrill Park on South Main Street.

Park Drive will be open to provide complete vehicular access to Buoy Park, Lermond’s Cove, Journey’s End Marina on Tillson Avenue, the Landings Restaurant and Marina on Commercial Street, and the Pearl restaurant. There will be no vehicular access to Main Street via the side streets between Park and Summer. Parking will be available behind the Thorndike block, accessible from lower Tillson, via Park Drive.

Public bathrooms will be available on Tillson Avenue.