BURLINGTON — The fallen Skagit River bridge on I-5 lies between Snohomish County and some of the area’s top tourism spenders, who drive south from Vancouver, B.C.

Just as the vacation season heats up, traffic is winding slowly along a detour between Burlington and Mount Vernon, and delays could discourage visitors.

The north end of the four-lane bridge collapsed into the Skagit River when a southbound truck pulling an oversize load apparently clipped overhead steel support girders about 7 p.m. May 23. Two vehicles ended up in the river when the bridge deck failed. Three people were injured.

“We definitely are concerned about the impact this will have in Snohomish County,” said Amy Spain, executive director of the Snohomish County Tourism Bureau.

About 70,000 vehicles per day use that stretch of I-5. All those vehicles and drivers will face detours adding time on local surface streets or miles on rural Skagit County roads to their trip while the Washington State Department of Transportation figures out how to repair the bridge, originally built in 1955.

When disaster has struck in other areas of the country, Spain said, tourism in those areas has been affected by public perception. If travelers hear of long delays, they get discouraged. But if visitors only have to drive an extra 30 minutes on a trip that typically takes three hours, they’re likely still to make the journey, she said.

Last year, visitors to Snohomish County spent $875.8 million, according to a March report by Dean Runyan and Associates. Restaurants were the biggest beneficiaries of those tourism dollars — to the tune of $244.2 million.

Travelers from Vancouver, B.C., make up Snohomish County’s third-largest market, Spain said. And they spend more than double that of people from, say, King County or Portland, Ore. That’s because most Vancouver travelers stay a night or two in area hotels and spend money at shopping centers like Seattle Premium Outlets at Tulalip.

Ken Kettler, president of the Tulalip Resort Casino, was keeping an eye on traffic May 24. At that point, he was hearing that drivers were having to spend an additional 40 minutes coming south through Skagit County. The resort was updating travel information on its website and social media channels.

“It’s going to take a little extra travel time,” he said.

About 20 percent of the Tulalip resort’s business comes from Vancouver tourists, Kettler said. Most of the casino’s visitors, though, are from the south — Marysville, Everett, north Seattle. Canadians “love to shop” and stay at the resort, he said. Kettler was optimistic about the Vancouver crowd.

“They’re explorers,” he said.

Tourism director Spain suggested that several Snohomish County businesses could benefit while the bridge is being repaired. Workers who will rebuild the bridge will need hotel rooms, food from local restaurants and fuel at area gas stations.

On the first full day of the bridge closure, at least, one Skagit County business along the alternate travel route west of I-5 already was seeing a boost.

Traffic along Best Road in front Rexville Grocery was busier than during the annual Skagit Valley Tulip Festival, said Joyce Welch, one of the owners.

“It is like I-5 out here,” Welch said, noting she’d never seen more traffic in her 14 years at Rexville, which sits about halfway between Conway and La Conner.

The store called in extra help to deal with the influx of customers. Typically open 7 a.m. to 7 p.m., Rexville Grocery could stay open longer to accommodate the extra people coming through.

Michelle Dunlop: 425-339-3454, mdunlop@heraldnet.com.