(CBS NEWS) -- Ski lifts ran on Independence Day at Squaw Valley Resort for the fourth time in history. But as the winter's record-breaking snow melts, it's creating raging rivers downstream where dozens of people have already been rescued from the Truckee River.

In the High Sierra of California, it's continuing to look a lot like Christmas -- but in July.

Two weeks after the official start of summer, skiers at Squaw Valley are refusing to let temperatures near 80 degrees melt away their favorite winter sport, reports CBS News correspondent Carter Evans.

"They're basically the same, they're just wearing less," Andy Wirth said of the difference between a winter skier and a summer skier. Wirth is the president and CEO of Squaw Valley.

Wirth thanks last winter's epic snowfall for his ability to keep the chairs lifting into July.

"We have this concept where we're going to run it as the 2016, '17, '18 season, we're going to take two ski seasons, put 'em together. This is absolutely uncharted territory," Wirth said.

But while some folks are rushing downhill, federal snowpack monitor Jeff Anderson is heading up to check on a data collection site nestled between runs.

"It basically is a big scale that measures how much weight there is in the snowpack," Andersen said.

Although one is empty, a few mountains over, a different station is still buried in winter.

"There's about four -- a little over four feet right now we're standing on" Anderson said. "We had two and a half times, that's 250 percent, means two and a half winters of snow, we got this one winter."

As it melts, most of the snow in these mountains flows downhill to the same destination: the 191-square-mile catch basin known as Lake Tahoe.

"We have seen more inflow to the lake this year than any year since we have records back to 1900," said U.S. District Court Water Master Chad Blanchard.

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