Skiers and snowboarders packed the slopes after a potent storm allowed Boreal near Lake Tahoe to become the first California resort to open for the season.
The 7,200-high resort atop Donner Summit opened Saturday after the first storm of the season put an abrupt end to a streak of record-high fall temperatures.
Boreal got up to 16 inches of snow, while nearby Alpine Meadows reported up to 2-3 feet.
"The first snowfall always gets people psyched for winter, but this is way more than we expected for the beginning of November," Alpine spokesman Brad Wilson said. "The snow depth on the base area sundeck alone is above my knees."
Boreal spokeswoman Jody Churich said she can't recall such a sudden change in the weather. The storm hit after Tuesday's end to unusually balmy late October temperatures.
"We went from mountain biking to skiing within days," she said. "The state climatologist says this is the most radical change in temperatures he's seen in 30 years. I believe it."
To the south, Mammoth Mountain is scheduled to open on Thursday, with a formal celebration on Saturday.
In the Tahoe area, Heavenly plans to open Nov. 21 while Alpine hasn't announced its opening day.
Boreal opened with a single chairlift and plans to open another lift on Sunday.
Cold temperatures are allowing resorts to crank up snow-making machines around the clock. Temperatures were expected to dip to 12 overnight at Tahoe.
Resort operators are hoping to swing into high gear by Thanksgiving Day, but acknowledge they need more help from above.
A winter storm watch remains in effect at Tahoe, where another storm was expected to bring a chance of snow Sunday night through Monday.
"Any help Mother Nature can give us while we're preparing to open - we'll take it," Alpine's Wilson said.
Chain controls were lifted by early Saturday afternoon on Tahoe-area highways, the California Highway Patrol reported.
The storm was blamed for a string of accidents Friday on Interstate 80 involving as many as 30 vehicles, including 10 big rigs near Donner Summit west of Truckee, Calif.
The main highway between Nevada and northern California was shut down for more than four hours in both directions. No one was killed, but one motorist was listed in serious condition at a Reno hospital.