YAKIMA – Yakima Valley wineries are worried that a rockslide that’s backing up traffic on I-90 east of Snoqualmie Pass could slow business over the Thanksgiving weekend.

Every year, wineries hold a three-day Thanksgiving in Wine Country event that draws hundreds of Puget Sound-area travelers. But state transportation officials have urged drivers to avoid the state’s main east-west artery through the Cascades this year due to rockslides and continued cleanup.

Paul Portteus, owner of Portteus Vineyards in Zillah, estimates about 80 percent of his 1,500 to 2,000 visitors during last year’s event journeyed from west of the mountains.

He worries that would-be buyers won’t make this year’s trip because of warnings from the Transportation Department, which he calls “scare tactics.”

“That will hurt business tremendously in Eastern Washington,” he said. “All kinds of business – hotels, restaurants.”

Traffic has been restricted 6 miles east of the 3,022-foot pass since Nov. 6, when refrigerator-sized boulders slid into the westbound lanes.

If Thanksgiving weekend traffic is as heavy as last year, it could cause delays up to five hours, Transportation spokesman Mike Westbay said.

He said keeping restrictions on I-90 is essential to work that could prevent further rockslides.

“That’s not an easy decision to make, but it’s the safe decision,” Westbay said.

Department of Transportation spokesman Stan Suchan said motorists who heeded the warning and took White and Stevens passes made traffic flow pretty smoothly on Snoqualmie Pass on the eve of Thanksgiving.

Last year, the state counted more than 44,600 vehicles crossing I-90 on the Wednesday before Thanksgiving. This year, that number dropped to less than 29,300 – about a one-third drop.

“It’s amazing,” Suchan said Thursday. “Drivers really saved us yesterday.”

Traffic on Snoqualmie Pass appeared to be light on Thanksgiving, the department said.

At the Yakima River Winery in Prosser, owner John Rauner called the warnings issued by the transportation department and Gov. Christine Gregoire “irresponsible,” but said he’s more optimistic that travelers will still visit.

“A lot of them already have hotel reservations, so I don’t think it’s going to deter all of them,” said Rauner, who had up to 1,000 people – eight out of 10 from Puget Sound area – visit his winery’s tasting room during last year’s Thanksgiving weekend. An average weekend this time of year usually draws about 10 or 12 people.

There are 45 local wineries participating in this weekend’s event, and like Rauner, they began preparing well in advance of any travel advisories.

“We put a lot of money into advertising on the westside and Portland, and we have a lot of food,” Rauner said.

Others, anticipating a decrease from westside travelers, focused more on the Yakima and Tri-Cities areas. The Wine Yakima Valley Association likewise is targeting eastside communities with advertising, said Barbara Glover, executive director.

She also said some wineries aren’t hiring the extra help they normally would.