Rivers, tubing, swimming & hot springs in Colorado

This trips up tubers, floaters, and anglers constantly, so it's worth understanding before you put in. In Colorado, the water is public — but the land under and beside a river is often private. Colorado's Constitution says the water of every natural stream belongs to the public. But a 1979 Colorado Supreme Court case, People v. Emmert, held that this does not give you the right to use the riverbed and banks where a river crosses private property. On most Colorado streams that streambed can be privately owned — and in Emmert, rafters were convicted of criminal trespass for touching the riverbed (with hands, paddles, and feet) to steer their rafts while floating through private land.

What that means on the water:

• Touching the bottom or banks on private land can be criminal trespass. This matters most for anglers wading and for tubers and floaters who stand up, stop, or drag. A 1983 state attorney-general opinion is often cited for the idea that floating through (without touching the bed or banks) isn't criminal — but that opinion isn't a binding guarantee, and landowners can still confront you or pursue civil trespass. It's a genuine legal gray area.
• "Navigable" rivers could be different. Under federal law, if a river was "navigable for title" at statehood (1876), its bed would belong to the public. But no Colorado river has been finally declared navigable for title in a way that settles everyday access. A long-running case by an angler, Roger Hill, tried to establish this on the Arkansas — but in June 2023 the Colorado Supreme Court dismissed it on standing grounds, ruling that only the state, not an individual, can ask a court to declare a river navigable. It never decided whether the river is actually navigable, so the question remains unsettled, and repeated bills to clarify it have failed.

How to read the flow (and the flags)

There's no universal "safe" number — a good float window is specific to each river and stretch. Find your exact reach on USGS Water Data, Dreamflows, or an American Whitewater page, read the current cfs and whether it's rising or falling (a hot afternoon or a dam release can spike it within an hour), and compare it to that run's known tubing range. Watch for posted flags or signs — the common pattern is green (open), yellow (caution, experienced only), red (closed) — and find the closure decision on the city, county, sheriff, or natural-areas page. Ignoring a posted closure can mean a ticket and a rescue bill. The water itself runs cold: high-country snowmelt sits in the 40s–50s through June and warms into the 60s by late summer (tailwaters below dams stay cold all year), so August is the realistic sweet spot.

Tubing rules & smarts

• Wear a real life jacket. Don't rely on the legal status of a tube (it isn't even a "vessel" in Colorado) — just wear a USCG-approved PFD on moving water. Some corridors require it: in the Arkansas Headwaters Recreation Area, every tube occupant must wear a life jacket. On an actual vessel, kids 12 and under must wear one.
• Floaties aren't life jackets. Water wings, pool toys, and flimsy single-chamber floats are toys, not safety gear — and many runs ban single-chamber devices outright. Use a real river tube and a real PFD, especially for kids.
• Scout for low-head dams and weirs. The urban creeks people tube — the South Platte through Denver, Clear Creek, Boulder Creek — have concrete drop structures that form a recirculating "hydraulic" below them. That backwash can hold and drown even a life-jacketed floater, so portage around any dam, weir, or smooth horizon line, and treat irrigation diversions and headgates the same way.
• Wear a helmet on whitewater-park stretches like Clear Creek, never tie tubes together in moving water, keep your feet up (don't stand in a current — feet get trapped under rocks), and know your exit points.
• Pack right: strap shoes or water shoes (not flip-flops — riverbeds hide sharp rock, glass, and rebar), sun protection (high-altitude UV reflects off the water), drinking water, and a dry bag. Leave the glass and alcohol at home — both are banned on many runs, and alcohol plus cold water drowns people.
• Start before noon (afternoon storms), use a shuttle so you're not stranded, and remember the water is snowmelt-cold even in July — see the Boating & Water Safety guide for the cold-water details.

The wild ones (free, primitive — and not guaranteed-access)

These are undeveloped, and access changes: some are a long hike, some have parking or trail restrictions, some need an overnight permit, and some have steep or unsafe access. Always check the managing Forest Service, BLM, county, or local page before you go. And like the river-access question above, some "secret" springs sit on private land or old mining claims where soaking is trespassing — confirm a spring is on public land first, respect closures and "no trespassing" signs, and don't escalate if confronted. A blog post from three years ago isn't current authorization.

• Conundrum Hot Springs — alpine pools at the end of a strenuous ~8.5-mile hike in the Maroon Bells–Snowmass Wilderness near Aspen; overnight camping requires a wilderness permit (and an approved bear-resistant container).
• Radium (riverside near Kremmling — limited access; respect BLM parking and trail restrictions), Penny (roadside on the Crystal River near Carbondale — steep rocky access, at your own risk), South Canyon (Glenwood), and Piedra/Rainbow (near Pagosa).

Etiquette & safety

• Reservations are increasingly required, especially at popular spots, and some sell out — book ahead.
• Clothing rules vary. Resorts generally require swimwear; a few places are clothing-optional, usually with age limits. Strawberry Park is clothing-optional after dark and adults-only after sundown; Orvis (near Ridgway) is clothing-optional for adults, with swimwear required for guests 17 and under. Check the current rule before bringing kids.
• Heat safety: limit your soak, drink water, cool off, and step out if you feel dizzy. Go easy or skip it if you're pregnant, have heart issues, or have had alcohol — don't drink and soak.
• Keep your head above water in natural/untreated springs. A rare amoeba (Naegleria) can live in warm freshwater and infects through the nose, so don't dunk your head, dive, or stir up sediment in untreated geothermal water. (Chlorinated resort pools are treated and safe — see Water quality & health.)
• Wild-pool etiquette: pack it in and pack it out (including toilet paper and human waste), no glass (broken glass in a soaking pool is a nightmare), no soap, shampoo, or sunscreen in the water, keep the noise down (many are camping-adjacent), and the small pools fill up — be ready to share or wait rather than hog one.

Beaches can also close for bacteria

Swim beaches are tested for bacteria (E. coli), not just algae, and can close until follow-up testing shows the water is safe. Important: an open gate reflects staffing, not water quality — test results can lag a day or two behind real conditions, and rain washes bacteria in, so the water is riskier right after a storm. Check the manager's current advisory page the morning you go, not just whether the beach looks open.

Dogs at the water

Colorado is dog country, and the water has dog-specific dangers. Toxic algae can kill a dog within hours — keep them out of scummy water, don't let them drink it or lick it off their fur, and rinse them right away. Standing water and popular dog-swim spots can also carry leptospirosis, parvo, and giardia. Most developed hot springs ban dogs from the pools entirely, and many swim beaches require a leash or prohibit dogs — check before you bring one, and watch for paw-burning hot pavement at the trailhead.

Don't drink the river

Never drink untreated stream, river, or lake water — even crystal-clear mountain water can carry giardia (a gut parasite). Filter, boil, or treat it.

Two more to know

• Swimmer's itch — a harmless but annoying skin rash from tiny parasites in some warm lakes; towel off and change out of a wet suit promptly.
• The amoeba (Naegleria) — extremely rare (typically fewer than 10 U.S. cases a year) but very serious. It lives in warm freshwater and infects through the nose — you can't get it from swallowing water, and treated/chlorinated pools are safe. In untreated warm or geothermal water, keep your head above water, don't dive or dunk, and don't stir up the sediment.