Winner: Lake Tahoe, California and Nevada
Sitting at 6,225 feet and ringed by the Sierra Nevada, the country’s largest alpine lake (191 square miles) is freakishly perfect for just about every outdoor pursuit. It’s surrounded by 18 ski resorts, myriad hiking trails into the west-side Desolation Wilderness, the technical, 14-mile-long singletrack Flume Trail on the east side, and long stretches of surprisingly solitary beaches—like famously remote Skunk Harbor—from which you can launch a kayak or sailboat or go for a swim. Lake Tahoe is also hardly a secret, but there’s a way to get your own slice of the Sierra oasis. Avoid the gambling masses at Crystal Bay on the north end and stay near Truckee at the Cedar House Sport Hotel (from $190; ). The owners have plotted out new custom escapes, providing the gear, food, maps, and guide (if needed). Sample itinerary: hike 8,742-foot Martis Peak the first day; mountain-bike the Flume Trail, with a cool-down dip at Secret Beach, on day two; then wind down with a mellow kayak or stand-up paddle on day three (prices vary depending on activity). SUPers: time your trip for the Ta-Hoe Nalu Paddle Festival, August 15–17 ().
Runner-Up: Squam Lake, New Hampshire
Nothing spells summer like a quiet cabin on a lake, and for that sort of leisure, it’s hard to beat 6,791-acre Squam. Base yourself at one of the 60 rustic cottages at century-old Rockywold Deephaven Camps, which offers family-style meals served in a post-and-beam dining hall, tennis on clay courts, a four-mile out-the-back-door hike up 1,260-foot West Rattlesnake Mountain, and kayak, canoe, Sunfish, and rowboat rentals (from $3,160 per week; ). For an overview of the Lakes Region, try the new inn-to-inn bike tours along the 59-mile Northern Rail Trail, which stretches from Lebanon to Boscawen (prices vary; ). No matter how you choose to tackle Squam, your evening entertainment consists of deciphering loon calls.