"My personal opinion," said Mark Tigan, "is that Rene Levesque is the best industrial developer that Vermont ever had."

Tigan should know. He is the executive director of the Community Development Corp. in this faded little mill town, which is enjoying a sudden economic revival as a result of the troubles that have plagued Canada's Quebec province, 60 miles to the north, since Premier Levesque's separatist government took power late in 1976.

Quebec's troubles have brought unforseen boom times to a number of small cities and towns scattered all across New England's chronically depressed northern tier. Residents of the province, uneasy over its shaky political and economic prospects, have begun moving their savings and business investments south in an increasing stream.

Canadian affairs specialists for First Boston Corp., one of the nation's biggest investment banks, estimate that hundreds of millions of dollars in business and real estate investments have been spread across the United States from Quebec since the movement to separate the province from Canada began picking up steam.

Much of that money has gone to more traditional investment centers such as Florida and the southwestern Sun Belt. But here in northern New England local economists estimate that investments and cash transfers from Quebec are running in the tens of millions of dollars.

The result has been a series of startling economic turns of fortune along the U.S. side of the border in the last year. Small cities and towns like Plattsburgh, N.Y., St. Albans, Vt., and North Troy, Vt., as well as coastal communities all the way over in Maine have reported an influx of Quebecois.

Here in Winooski, a community of 7,300 whose major textile industry closed up more than two decades ago, city officials were wrestling with a persistent unemployment rate of as much as 17 percent last year with no relief in sight.

Then, in a rush that still leaves Winooski officials a little astounded, more than 100 firms from Quebec made inquiries here about moving or setting up new subsidiaries in the area. Winooski's municipal industrial park, which had been lying fallow since was built in 1975, was suddenly sold out.

"Here, take a development brochure - take two," said Tigan. The handsome brochures, with a seductive vista of autumn foliage on the cover, are no longer needed, Tigan happily explained. "We're full and turning people away."

Tigan and other Winooski oficials now confidently predicg that in another 18 months, when the five Canadian firms which are locating in the industrial park are moved in, the city's unemployment rate will be down around 4.5 percent, well below the national average. Money in Suitcases

IN NORTHERN NEW YORK, just across Lake Champlain from here, banks in Plattsburgh and other small communities experienced such a flood of Canadian money after Levesque's Parti Quebecois took over that several began discouraging deposits from Quebec.

"We has people arriving with $50,000 or more stuffed in suitcases," said Plattsburgh bank official Warren Dixon. Some women marched straight through the bank to the ladies room and pulled thick wads of bills from their stockings, Dixon said.

Dixon's National Savings Bank and several other slapped ceiling on the amount of money they would accept from prospective depositors with Quebec addresses. The American bankers said they feared that a change in the political climate would mean a run on their banks, which offer substantially lower rates of interest than their Canadian counterparts.

As a result of the ceiling, Quebec residenys began buying up every safe deposit box in town. George Coleman, northern vice president for eight bank branches belonging to an Albany-based holding company, First Commerical Banks Inc., said several of his branch banks were left with no safe deposit space after the cash influx from Quebec.

"Let's face it," Coleman said. "Nobody knows what's going to happen up there. A lot of people were refugees who came to Canada from Europe and they know what can happen to a country's money supply."

The flow of money and business investment from Quebec has stretched all across northern New England. In North Troy, high up in the remote northeast corner of Vermont, local officials had all but given up hope of attracting any industry to replace a woodworking plant that removed 150 jobs from the town's 750 residents when it closed eight years ago.

Last summer Guy Laflamme, owner of a woodworking firm in St. Croix, Que., broadly hinted to North Troy officials that he would open a U.S. subsidiary there. Laflamme confirmed his intent not long ago, bringing such joy to North Troy that the town threw a party in his honor.

Other border communities in New Hampshire and Maine have also reported Quebecois depositing money in local banks and scouting business prospects. In Old Orchard Beach, Maine, a traditional summer resort for French-speaking Quebecois, local bank officials said those who support Parti Quebecois are hedging their bets by looking for U.S. investments.

Edgy town officials, concerned that any effort to pick up business from the separatist issue could hurt tourism, insist that the recent flurry of inquiries about investment possibilities has nothing to do with politics. But privately one senior banker in the Maine seaside town said, "Is there money coming down here because of the separatist push? Yes. Are they looking of investments? Yes. There are a lot of very nervous people coming through here from Quebec looking for places to put their money. They're investing all the way to Florida." "I Picked the Wrong Place"

WHILE THE MAJORITY of those seeking investments along the Maine coast are French-speaking residentsof Quebec, most of those in northwestern New England are Europeans who arrived here as refugees.

Frank Arvai, whose Champlain and Jay Development Ltd. opened its U.S. office just off Plattsburgh's main street last year, was a Hungarian freedom fighter before emigrating to Canada in 1957.

"Unfortunately," said Arvai, who is building his second apartment development in Plattsburgh and has applied for U.S. citizenship, "I picked the wrong place to settle."

When the Parti Quebecois took over, he said, his firm's annual gross business dropped from $30 million to under $1 million on its Montreal investments. "Property values dropped as much as 40 percent up there and now we're stuck with 32 condominiums in Montreal we can't sell. To expand up there at this stage of the game would be suicide."

Like a number of other former refugees who have moved investments to the United States, Arvai said his real worry is that the Quebec monetary system may be undermined of Levesque's party carries out its intention to separate.

"In Hungary things came apart after World War II when they started printing their own money," Arvai said. "What is it if you have $10 million in the bank and can't buy a dozen eggs?"