It will be a landmark event for the Island and for the Martha's Vineyard Preservation Trust when the Old Sculpin Gallery opens its doors on Thursday afternoon to unveil a 40-piece retrospective of paintings by the old master of a modern era, Ray Ellis. The oil and watercolor landscapes selected for the three-day show - gathered from private collections across the country - were all painted en plein air on the Island. The show will close just two days later at 9 p.m.

"We were pretty lucky at finding the ones we'd chosen," Mr. Ellis said of the paintings while sitting in his mercifully air conditioned Edgartown work studio on a sweltering Wednesday in early August. "There's hardly a spot on the Island that's not covered."

The retrospective at the Old Sculpin Gallery will mark the trust's first formal event there since it acquired the gallery from the Martha's Vineyard Art Association last year. Preservation Trust director Christopher Scott approached Mr. Ellis soon after the acquisition.

"When we first acquired building we started to talk about this idea," said Mr. Scott. "There's never been a Vineyard retrospective [of Mr. Ellis's work] and we thought it would be a fitting tribute to Ray - and something the public will be very interested in seeing."

Mr. Scott was inspired both by Mr. Ellis's extraordinary career and his prolific generosity to the Island, contributing to "just about every nonprofit on the Island."

Mr. Ellis has been an artist for roughly 70 years, during which time he has produced several thousand works and painted on all seven continents. Yes, that includes Antarctica - and no, the watercolors did not freeze while he was painting. The weather during the day was quite nice, actually, which is not always the case in New England.

"When I used to paint winter scenes here in the states, the water would freeze," Mr. Ellis said. "That's how I learned to paint fast," he added, smiling broadly.

Ray Ellis is 85, though he may tell you with a straight face that he's 69 - and you might believe him for the fraction of a second before he bursts into deep laughter. His work belongs to permanent collections in about 15 American museums. Fourteen books have been published featuring his paintings, including three collaborations with Walter Cronkite in the 1980s. The Edgartown Art Gallery, where he sells the majority of his work on the Island, has sold $2 million of his work. The New York Graphic Society, which distributes to 160 countries, has sold 120,000 of his prints.

"People will say, ‘We were in Singapore and saw a painting of yours up on the wall!' " Mr. Ellis said.

Mr. Ellis also has a gallery of his work in his former home base of Savannah, Ga. In 2004, the gallery put together a retrospective that included 82 of his paintings.

"He's remarkably vigorous and continues to be one of America's top landscape artists," Mr. Scott said.

Next week's retrospective extends back in time as far as the Philadelphia-born artist has been coming to the Island - 35 years, of which he has lived 20 in Edgartown.

"It's actually exceeded my expectations," said Mr. Scott, reflecting on his original vision of the show, which was the idea of Pat Snyder, Preservation Trust president Bob Snyder's wife. "We've been working very hard on it for a year."

Mr. Ellis and his wife Theodora (Teddie) hand picked each of the 40 pieces that will be in the retrospective. With most of the paintings in private homes, the task of collecting them was a challenge. The Edgartown Art Gallery tracked down many of the owners' addresses through their records.

"There was a lot of trouble," Mr. Ellis said. "Some people had moved away from the Island." But in the end, they tracked down every single painting they wanted for the show. The landscapes do appear to incorporate every recognizable - and some unrecognizable - Island scenes: Gay Head, Cape Pogue, the Edgartown light, the East Chop light, the Black Dog, the agricultural fair, Allen Farm, the Flying Horses, Illumination Night, boat races, fishermen and beach scenes.

"I don't think we could have put on a show with more than 40 paintings," Mr. Ellis said of the exhaustive effort of finding all of the paintings. Three or four were picked up over the weekend at a private company in New York. Another painting comes from a former Island woman they traced to Florida. Three come from the personal collections of Mr. Ellis and his wife.

"Those have been our favorites that we have kept," Mr. Ellis said.

Some of the pieces evoke fond memories of the early days of painting outside on the Vineyard. One summer in 1978 or 79, Mr. Ellis was visiting the Island for a month from New Jersey.

"I was painting on Davis Lane, on the tailgate of my station wagon," Mr. Ellis said. "This lady came up behind me on a bicycle and said, ‘Can I watch you paint?' " The artist said yes. "When I was nearly finished with it, she said, ‘You paint just like a painter in New Jersey called Ray Ellis.' " The woman lived about two miles from Mr. Ellis's gallery. "I said - I am Ray Ellis!" Mr. Ellis exclaimed, laughing heartily.

Mr. Ellis's body of work continues to expand. He still paints every day in his home studio above the garage.

"Some days I'll paint from 9 to 4, or other days I'll come up and plan something," he said. "Whether I'm painting or not, I'm painting in my mind."

And his success continues to grow.

"The last two years, everything happened that I dreamed could happen, and never expected would," Mr. Ellis said. Goals he set many years ago, like having a museum show, having pieces in permanent museum collections and having a book of his work - have all been reached.

"It's my idea of immortality," he said. "The greatest compliment you can have is when people come into a room and say, ‘Oh, you have a Ray Ellis.'"

The Ray Ellis retrospective will run from 1 to 9 p.m. on Thursday, August 10, and from 9 a.m. to 10 p.m. on Friday and Saturday at the Old Sculpin Gallery on Dock street in Edgartown. Admission is free. A 48-page full-color catalogue of the show and prints of a piece Ellis was commissioned to paint specially for the event, will be on sale. Proceeds will go toward upkeep of the building.