ROCKLAND – The essential ingredient for making the Maine Lobster Festival a success: a ton of volunteers.

Over the past 56 years, the volunteer force behind the annual event has grown to more than 1,000 people, many of whom give up their vacation time – and often money – to put together a celebration that keeps giving back to the community.

One year the Maine Lobster Festival used proceeds to buy the land above Harbor Park, which was dedicated as Mildred Merrill Park.

Another year, the group used the profits to buy the city a brand-new ambulance that cost about $80,000, Festival President Ed Kolmosky said Wednesday.

Then there was the year the organization paid $34,000 to pave the public landing.

Most recently, the festival organization pledged $200,000 over five years to assist with renovations of what is being called the Gateway Center. The center will include a tourist information office, the local Chamber of Commerce, a Maine Lighthouse Museum and other office space, as well as exhibits from area museums.

The building at 1 Park Drive is being leased by the city from MBNA to accommodate the Rockland Police Department in the ground level.

The Gateway Center will be on the top floor.

Each August, an army of volunteers begins setting up the festival a week ahead of opening day.

There are tents, tables, chairs and booths to set up, as well as food supplies and paper products to organize for the food tent.

Come opening day, the rush is on.

Cooking for 100,000 visitors over the course of the five-day event is no small feat, and someone has to do the dishes even if most of the dinnerware is disposable.

Longtime volunteer Julie Raye of Rockland joined the festival activities 14 years ago.

“I came down for a four-hour shift,” she said, “and I ended up staying the whole week.”

Now, Raye is a festival director and in charge of the food tent and volunteers, along with director Paulette Sylvester, also of Rockland.

While setting up on Tuesday, the two women said volunteers come in droves from out of state.

A Colorado man who organizes a St. Patrick’s Day parade in his community sent Sylvester an e-mail recently, offering to volunteer at the Maine Lobster Festival, she said.

Families from Pennsylvania, New York and Connecticut also have offered their services.

Raye hangs festival T-shirts in her store window at House of Cards in Rockland and gets lots of queries about buying them, she said.

People ask, “How much is that T-shirt?” and she replies, “Four hours of volunteering.”

Volunteering for Raye is being involved, knowing what’s going on and having some control over it, she said. But mostly, it’s “camaraderie” with the other directors and meeting “so many nice people here, from away.”

First year volunteer Lynn Archer of Thomaston said one reason she opted to join in the fun is “it’s just a great feeling of community. A lot of the local folks put their heart and soul into making this a success.”

“Without [volunteers], this just couldn’t happen,” Raye said.