OLD ORCHARD BEACH – With Canadian currency at a 28-year high against the U.S. dollar, business owners are preparing for a rise in tourists from north of the border.

The Canadian dollar has jumped more than 40 percent in the past four years and reached heights this month not seen since 1978, giving visitors more bang for the loonie, the popular name of Canada’s $1 coin that features a loon.

Old Orchard Beach has been a popular vacation spot for French-speaking Canadians for decades, but business dropped off when the Canadian dollar was on the skids.

Pierre Janelle, a third-generation motel owner, remembers when Canadians accounted for 80 percent of customers during the peak months of July and August. In recent years, Canadians have made up barely 5 percent of his clientele.

“Our business has been shifting away from Canadians, and that’s because of the Canadian dollar,” said Janelle, owner of The Edgewater motel. “Now we’re hearing from people who say, ‘We haven’t been there in 10 or 12 years and we’re coming back.'”

The Canadian dollar wasn’t always in the doldrums. Back in the 1950s and briefly in the ’70s, it was worth more than the American dollar.

But it has been in the dumps for nearly three decades now, giving Canadians diminished buying power when they visit the United States.

It bottomed out in 2002, when it was worth just 62 U.S. cents, meaning it took $1.60 in Canadian money to buy $1 in greenbacks.

Since then, the Canadian dollar has been growing in value; in May it broke the 90-cent level for the first time since 1978. Economists say the loonie is showing strength because of a strong Canadian economy and high prices for oil, gas, lumber and other commodities from Canada.

That’s good news for resort towns such as Old Orchard Beach that rely on Canadians for business.

Here, Canadian flags fly outside many businesses, French-language Canadian newspapers are found in motel lobbies, and fries with gravy and cheese – a Canadian favorite – are served up alongside fried dough and fried clam strips. For people in Quebec, Old Orchard offers the closest sand beaches a half-day’s drive away.

When the loonie was weak – it was worth less than 70 U.S. cents from 1998 into 2003 – a lot of Quebecers who previously came to Maine for vacation opted instead to go to New Brunswick or Ontario, said Guy Dagenais of Beloeil, Quebec. Others switched to cheaper motels or came in the off-season when the rates were lower.

Canadians’ travel patterns are now changing, Dagenais said as he ate a slice of pizza in Old Orchard Beach last week with his girlfriend.

“After visiting there for a few years, people are coming back to the United States with the stronger dollar,” Dagenais said.

Cross-border shopping and travel is on the rise along the entire U.S.-Canada border, said Manny Witt, director of the New England Tourism Office in Montreal, which promotes tourism to the six-state region.

Retailers from Maine to Washington state are reporting strong sales to Canadians because of the favorable exchange rate, he said.

Besides the increased buying power of the loonie, the U.S. is an attractive destination because taxes are lower and gasoline is cheaper than in Canada.

“People are saying they haven’t seen this happening since the early ’70s,” Witt said.

Some of the New England hot spots for Canadians this summer are Old Orchard Beach; Hampton Beach, N.H.; Boston; Cape Cod; and Newport, R.I., Witt said.

In New Hampshire, the state is increasing its advertising in Canada this summer and has added a French-language welcome page to its tourism Web site, said Travel and Tourism Director Alice DeSouza.

In Vermont, Canadian visits are tied to the Canadian dollar at the Shelburne Museum. “If the Canadian dollar’s very weak, we’ll get a certain number,” said spokesman Sam Ankerson. “If the Canadian dollar is strong, we’ll have twice as many.”

In the first three months of the year, the number of Canadians traveling to the U.S. went up more than 5 percent from 2005, according to Statistics Canada.

A couple of weeks ago, Witt’s local bank ran out of U.S. currency because so many people had bought it up for trips across the border.

One day last week, his office received nearly three times the number of requests from Canadians for tourism brochures to Maine than on the same day last year, he said.

At the Beau Rivage Motel in Old Orchard Beach, desk clerk Danielle Coombs took French lessons over the winter in anticipation of an increase in visits from French-Canadians. The lessons are paying off.

“It’s come in handy,” she said, “since most of our reservations are Canadian right now.”

While the strong Canadian dollar is bound to benefit the Maine tourism industry, it could end up pulling more Canadian tourists into the Boston market than into Maine, said Charles Colgan, a professor at the University of Southern Maine.

And no matter how strong the loonie gets, it’s unlikely that Old Orchard Beach or any Maine resort will experience the Canadian boom of decades past when families came year after year.

“People got out of the habit of doing that,” Colgan said. “It doesn’t seem like, even with the Canadian dollar up, people will re-establish those travel patterns.”