Hot springs near Denver

About 30 minutes west of Denver, this historic resort dates its baths to 1863 and has the trimmings to match: a mineral-water pool in an atrium planted with banana trees, men's and women's geothermal caves, cedar and outdoor tubs, private baths and a mud bath called Club Mud. The trick is the calendar. On weekdays the caves are swimsuit-optional and open 8:30 am to 9 pm; on weekends the caves and pool run in timed blocks and suits are required. They don't publish a price you can read online, so call before you go.

In a town actually called Hot Sulphur Springs, this resort runs 20 gravity-fed pools plus private baths, with water the operator describes as natural and untreated. Know the lightning rule before you go, because every pool and shower closes whenever a strike is within five miles. The resort opens every day of the year, 8 am to 10 pm, and the public pools are walk-in only; book ahead just for rooms, massages or a private bath. Adults pay $30 or $35, and late entry after 8:15 pm drops to $17, a fine deal if you're passing through in the evening. Last walk-in is 9:15 pm.

Buena Vista's low-key option: natural artesian water in soaking tubs, a river plunge and a dry sauna, open 8 AM to midnight every day. No reservation needed for a soak, so you can simply turn up. A soaking pass is $45 and towels cost extra, so bring your own. Stay in a lodge room or cabin and the soaking comes with the bed, which is the easy way to get a late-night soak with a short walk home afterwards.

A free, primitive warm pool on the Upper Colorado River near Kremmling, and getting there the right way matters. The old social trail from the Radium Recreation Area is closed to protect wildlife habitat, there's no designated route from the recreation site, and you can't park along narrow Radium Road. Instead, follow Trough Road (County Road 11) to Warm Springs Road, 1.5 miles northeast, where the foot-only Warm Springs Trail begins. BLM doesn't describe the pool's temperature or condition, so keep expectations modest. The BLM campground closes Dec 1 to Mar 31; otherwise single sites are $6 a night.

The big one, and literally so: Glenwood's Grand Pool is two acres of mineral water kept around 90 to 94°F, with a Therapy Pool near 104°F for serious soakers and cold plunge tubs at about 52°F in the Yampah Mineral Baths. You don't need a reservation, and a day pass covers re-entry all day, so you can wander town and come back. Expect $42 off-peak and $60 in peak season. Both main pools run 8 am to 10 pm; the Yampah baths go adults-only after 5 pm, worth knowing if the kids are with you.

Glenwood's second big soak spreads across 35 pools from 89° to 108°F, plus a Sauna Summit of five saunas and three plunge pools at 45° and 55°F. Book online, where tickets are $5 cheaper than at the window, and prices move by date, from $43 for family-friendly Select Access up to $135 for the 21-and-over Premier tier. Children under 5 can't use the geothermal pools, and under-21s stay out of the Sauna Summit and WorldSprings area. Open 9 am to 10 pm daily, apart from scheduled maintenance closures.

A 70-acre resort at 8,250 feet on Chalk Creek, between Buena Vista and Salida, with a pool for most moods: soaking, exercise and infinity pools, a water slide for the kids, and creekside hot springs where you blend cold creek water with hot until it suits you. The operator says the mineral water is odorless. Day passes are sold at the door with no reservation needed and let you come and go from 9 am to 9 pm. Prices appear only as an image on their site, so expect to learn them at the desk. Hotel rooms and cabins are on the hillside.

Built in 1937 as a Works Progress Administration project, Salida's indoor pool is one of the largest indoor hot springs pools in the nation, according to the city. Mineral water piped in from 4.5 miles away fills a 25-meter lap pool at 82 to 84 degrees and a leisure pool at 97 to 100, with private soaking pools for hire. Adults pay $17 and kids less. Access is well thought out, with an ADA lift, step entries and a zero-entry area into the leisure pool. Being indoors, it's the one to remember when the weather turns. Hours change by season and are posted monthly.

Natural hot springs fill stone-masonry pools here in Steamboat Springs, near Routt National Forest. Plan around three things. Book first, since two-hour slots open 30 days out and a reservation also guarantees parking. Bring cash, the only payment taken on site ($30 adults, $20 for 17 and under). And mind the road, because from November 1 to May 1 county law requires 4WD with snow tires or chains. Clothing goes optional after dark, so minors aren't admitted after sundown. No pets. Cabins book 90 days out.

Out on the broad floor of the San Luis Valley near Moffat, this small spa keeps three pools at different temperatures, a cold soak, hot tubs and a dry sauna, and lets you sleep in a hotel room, a yurt, a tipi or your own RV. Day guests come 9:30 AM to 9:50 PM Sunday to Thursday, with an earlier 8 PM close on Friday and Saturday; overnight guests get longer hours. Day rates aren't posted online. Their phone line has been listed as temporarily down, so email is the surer way to reach them.

A clothing-optional hot springs preserve in the San Luis Valley, owned and run by the nonprofit Orient Land Trust, which calls the property a delicate ecosystem and asks you to treat it that way. Admission is limited, and day passes and overnights are both reserved by phone; walk-ins get in only if space remains, so call ahead. A day pass is $20 (arrive 11 am to 6 pm, stay until 8 pm) and children 15 and under are free. Cabins and camping on site turn a day trip into an easy overnight.

Saratoga's town pool costs nothing and never closes: it's free and open 24 hours a day all year, on the west bank of the North Platte behind the municipal swimming pool at the east end of Walnut Street. The main pool runs from about 106 degrees at its coolest to 119 at the hot end, which is hot enough to scald, so test the water before you settle in or use the Not-So-Hot Pool next door, around 100. Swimsuits are required, and alcohol, tobacco, glass and open containers are banned. There's a bath house with showers and restrooms.

The pools here are for hotel guests only, and there's no public day pass. The one way in without a room is a spa treatment, which includes day use of the pools and fitness center. Guests get a 70-foot mineral pool at about 96-98 degrees and teepee-covered soaking pools at 100-112, all heated by the spring. Hours are 7 am to 9 pm, apart from maintenance: the big pool is closed Tuesdays and the teepee pools Wednesdays, each until 5 pm. If you just want a soak, the free Hobo Pool is two blocks away.

This is the backcountry soak Colorado hikers save for: a natural pool high in the Maroon Bells-Snowmass Wilderness, about 8.5 miles up the Conundrum Creek valley from a trailhead near Aspen. Day use is free, which makes for a very long day on foot. Sleeping up there takes a Recreation.gov permit year-round, and you camp only in the site you reserved. Snow buries the trail from roughly October to late June, so aim for July through September, as the Forest Service suggests. Leave the dog at home, pack a bear canister and forget the campfire.