New Hampshire has lost about 60 percent of its downhill ski areas since the 1970s, according to a study released last week.
Back then, skiers had their pick of roughly 65 ski areas, compared to about 20 now, said Cliff Brown, a sociology professor at the University of New Hampshire.
He said the industry used to be dominated by small, family-run resorts several decades ago. Now, the surviving resorts typically offer snowmaking, trail-grooming, lodges, real estate development and offseason activities.
Ski areas also now are concentrated in the central and northern regions of the state, he said. Since the 1970s, the state's winters have warmed about 3.8 degrees, resulting in less consistent snowfall.
Brown's report comes as the remaining resorts prepare to open for the season.
Last year, at least one New Hampshire ski area opened in October after an early storm left behind more than a foot of snow. But most ski areas will be back to traditional November starts this year.
A dusting of snow Oct. 23 gave some ski areas reason to hope for early openings, but a burst of warm weather last week ended those dreams.
"It's been pretty typical, we had some pretty good storms in October that would have been promising if it had been January," said Jim Mansfield, meteorologist at the National Weather Service in Gray, Maine.
Waterville Valley, which opens Saturday, has one of the earliest opening days. Bretton Woods, which ran its snow guns for the first time in late October, plans to open in the next week or so.
Attitash ski area and Wildcat Mountain both plan to open Nov. 24, followed by Sunapee the next day. Cranmore Mountain Resort opens Dec. 9 and King Pine on Dec. 15.