Not sure if there is a definitive place on FTOL to put this, but here's my lifetime ski area count as of 18 March 2024. It's not common for me to add new areas to my list at this stage of life, but this winter I skied Monarch, CO and Diamond Peak, NV for the first time.
Ski Areas Visited, Lifetime, Dec 1967 - March 2024 (98 total)
US
California (8): Alpine Meadows, Heavenly (including Nevada side), Homewood, Kirkwood, Mammoth, Sierra at Tahoe, Squaw Valley, Sugar Bowl
Colorado (15): Arapahoe Basin, Aspen Highlands, Aspen Mountain, Beaver Creek, Breckenridge, Copper Mountain, Crested Butte, Eldora, Loveland, Monarch, Snowmass, Steamboat, Telluride, Vail, Winter Park
Maine (4): Mt Abram, Saddleback, Sugarloaf, Sunday River
Maryland (1): Wisp
Massachusetts (1): Wachusett Mountain
Montana (1): Big Sky
New Hampshire (7): Attitash, Black Mountain, Cannon Mountain, Gunstock, Loon, Waterville Valley, Wildcat
New Mexico (3): Red River, Ski Santa Fe, Taos
New York (5): Gore Mountain, Hunter Mountain, Plattekill, Whiteface, Windham
Nevada (1): Diamond Peak
Oregon (1): Mount Bachelor
Pennsylvania (8): Blue Knob (first place skied - December 1967), Camelback, Hidden Valley, Laurel Mountain, Liberty Mountain Resort, Roundtop, Seven Springs, Whitetail
Utah (10): Alta, Brighton, Deer Valley, Park City (before and after joining The Canyons), Park West (defunct), Powder Mountain, Snowbasin, Snowbird, Solitude, Sundance
Vermont (12): Jay Peak, Killington, Mad River Glen, Magic Mountain, Mount Snow, Okemo, Pico, Smugglers Notch, Stowe, Stratton Mountain, Sugarbush, Suicide Six
Virginia (4): Bryce Resort, The Homestead, Massanutten, Wintergreen, (I also visited now defunct Big Devil/Rappahannock/Skyline ski area in the early 1970s on a winter day when it was unexpectedly closed and did not get to ski it.)
West Virginia (3): Canaan Valley, Snowshoe, Timberline
Wyoming (2): Grand Targhee, Jackson Hole
International
Austria (5): Bad Hofgastein, Flachau, Saalbach-Hinterglemm-Leogang, Zauchensee, Zell am See
Canada (7): Lake Louise, Le Massif, Mont Sainte Anne, Mt. Norquay, Revelstoke, Sunshine Village, Whistler-Blackcomb
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Which are my favorites? Here's an article I wrote two years ago on that subject, it's sort of slanted towards a Mid-Atlantic audience:
https://www.dcski.com/articles/1657
Recently (earlier this month) I had two really fine days on the Olympic Valley side of Palisades-Tahoe (also skied it and Alpine Meadows once ten years ago) and I'd now rank that in my top 20 fav ski areas especially when you add-in Alpine Meadows. Loved the high alpine terrain at OV.