Conundrum Hot Springs, CO 18 miles (Difficult)
Take a sparkling warm-water pool, place it just so below 14,265-foot Castle Peak, add alpine views and meadows, and you have the paradise known as Conundrum Hot Springs. A place this special is no secret, but you can avoid the mule train of hikers by skipping the standard approach from Aspen; instead, hike in from the Crested Butte side via the Copper Creek Trail, and score even better vistas of the surrounding Maroon Bells-Snowmass Wilderness on the way. After topping out at 13,057-foot Triangle Pass, you’ll descend to Conundrum. Do this round-trip late or early in the season for the best chance of solitude.
Info (970) 641-0471
Goldbug Hot Springs, ID 4 miles (Moderate)
Here’s a bathtub with a view: Perched some 800 feet above Warm Springs Creek, with steaming cascades trickling in from above and a canyon yawning below, this remarkable 100°F pool has a view of mountains rippling away to the horizon. The round-trip hike skirts sagebrush-covered slopes and climbs nearly 1,000 feet, with most of that gain crunched into the last half-mile. Then, bliss.
Year-round (though you’ll want extra traction in winter, when trails are snowpacked and icy)
Info (208) 756-5100