Trail etiquette and Leave No Trace in Boulder

Boulder's trails carry a lot of people. The rules that keep them working aren't complicated, but a few of them are counterintuitive, and one of them (walk through the mud) is the opposite of what most visitors instinctively do. Here's what the City of Boulder Open Space and Mountain Parks (OSMP) actually asks, in the order you're likely to need it.

The short version: yield to everyone, and if you're on a bike, yield to literally everyone including uphill riders. Walk through mud, not around it, and check for muddy trail closures before you drive out. Stay on the trail, especially in Habitat Conservation Areas, where leaving it needs a free permit. Leash up at trailheads, pick up dog waste and carry it out, don't pick the wildflowers, and keep your speaker off.

Who yields to whom: the right-of-way triangle

The classic trail triangle is bikes yield to hikers and horses, hikers yield to horses, and downhill yields to uphill. Boulder's version is close, but it's worth knowing exactly how OSMP words it, because the wording is broader than the diagram:

• Bikes yield to everyone. OSMP's biking rules tell cyclists to "yield the right-of-way to all other trail users and cyclists traveling uphill." That's hikers, runners, horses, and other riders climbing toward you. It also asks riders to anticipate people around corners and blind spots, be prepared to stop, alert others in advance when passing, and control their speed.
• Everyone yields to horses. OSMP states plainly that its regulations require all other visitors to yield to equestrians. The equestrian page adds a practical caveat: sometimes it's easier for the rider to yield instead, so read the situation. If you do step aside for a horse, move to the downhill side where you're easier for the horse to see, and say hello so it hears a human voice.
• Uphill has priority, and OSMP spells it out for bikes. The uphill rider explicitly has the right-of-way in OSMP's own rules. Hiker-to-hiker, uphill priority is a widely used convention rather than a written OSMP regulation, and climbers often wave you through anyway. Either way, whoever has the easier place to stand should be the one who steps aside.

OSMP's own one-line summary for everybody, printed under its Leave No Trace guidance, is the simplest thing to remember: "Yield to all, but stay on the trail if you can." That second clause matters. Yielding by trampling the vegetation beside the trail defeats the purpose.

If you ride, our Boulder mountain biking guide covers which trails allow bikes in the first place, since OSMP only permits riding on trails posted with the bike symbol and rangers will write a summons for riding where bikes aren't allowed.

Muddy trails: walk through, not around

This is Boulder's most-violated rule, and it's violated by people trying to be careful. When you sidestep a mud puddle, you crush the plants at the edge of the tread. Do that a few hundred times and the trail widens, then braids into two or three parallel paths, and the erosion follows.

OSMP's instruction is direct: be ready to get muddy and step right through puddles, because "boots dry overnight; plants take years to recover." If you don't want to slip or get muddy, OSMP's suggested alternative isn't to tiptoe around it, it's to pick a different dry trail or a hard surface until the trail dries out. The same rule applies on horseback, where OSMP tells riders to ride through the mud rather than around.

For bikes the guidance goes further. OSMP asks riders to practice minimum-impact cycling by avoiding muddy trails altogether, along with skidding, hard braking, and shortcutting, and warns that riding wet or muddy trails causes serious erosion and may result in a temporary trail closure.

Staying on trail, and where leaving it needs a permit

OSMP's case for staying on trail isn't just about erosion. Colorado State University researchers working on OSMP land found that fewer birds nest near trails and that young birds survive less often near a trail, and that some species aren't found until several hundred yards out. Animals get used to predictable traffic on a trail corridor. When people wander off it, the threat becomes unpredictable.

OSMP also names rare species its land protects, including the Preble's meadow jumping mouse, the peregrine falcon, and the Ute ladies' tresses orchid. And when people trample the vegetation beside the trail, weeds are more likely to replace the native plants that were there.

The practical rules:

• Habitat Conservation Areas need a permit to leave the trail. OSMP's Off-Trail Permit Program issues a free permit to travel off designated trails in Habitat Conservation Areas (HCAs). Off-trail travel on foot or horseback in an HCA requires it, and off-trail horseback riding is prohibited outright in the Eldorado Mountain HCA.
• Bikes stay on trail everywhere. Biking is allowed only on designated multi-use trails, bikes must remain on trail, and rangers issue summonses for riding off-trail or on trails where biking is prohibited.
• Closed means closed. Avoid areas that are unmarked, closed for revegetation, or signed as sensitive. Seasonal closures, like the ground-nesting bird closure from May 1 through July 31 in parts of the southern grasslands, prohibit off-trail travel during those windows.
• Off-trail elsewhere: allowed, but discouraged. Outside HCAs, OSMP says off-trail travel is permitted in most areas but asks you to refrain, because sticking to designated trails protects fragile habitat from damage and erosion.

Dogs: the Voice and Sight tag, and the poop rule

Boulder's off-leash system is the Voice and Sight Tag Program. A registered, tagged dog can be off leash on designated City of Boulder OSMP trails, but the standard OSMP applies is strict: your dog stays in your sight and under voice control, and comes to you immediately on first command in every situation. Dogs must be leashed at trailheads, and some trails and seasons are leash-only regardless of the tag.

OSMP's etiquette guidance goes past the letter of the rule. It asks you not to let your dog approach other people unless invited, to ask first if you're unsure, and to leash up if you're not confident your dog can meet the voice and sight standard. Not everyone on the trail wants to meet your dog, and chasing wildlife makes animals burn energy they need.

On waste, the rule has a detail people miss: you must pick it up and carry it out, and leaving a bagged pile on or near the trail, even temporarily, is a violation of OSMP regulation. Bag it, carry it, and put it in a trash can. Dog waste also loads the soil beside the trail with nitrogen, which favors weeds over the native plants that evolved in nitrogen-poor ground.

For the full rundown of which trails allow dogs, how the tag works, and where dogs are banned entirely, see our guide to hiking with dogs in Boulder.

Wildflowers, rocks, and wildlife: leave it all where it is

Picking flowers or berries, collecting rocks, cleaning climbing routes, and marking a trail with flour or flagging tape aren't just frowned on in Boulder. The City of Boulder says plainly that these activities are illegal on OSMP land. One picked columbine feels harmless; a few million visitors a year makes it not harmless.

This bites hardest in wildflower season, when the mesas and the Indian Peaks basins fill with color and people want a bouquet. Take the photograph instead. Our wildflower hikes guide has the trails and the timing.

For animals, the etiquette is the same idea: watch from a distance and never feed them. Boulder has black bears, mountain lions, prairie rattlesnakes, and moose, and a fed animal usually ends up a dead animal. Our Boulder wildlife safety guide covers how to react to each of them.

Music, headphones, and phones

Boulder's guidance here is stricter than most people expect. OSMP's low-impact conduct guidelines ask visitors to keep cell phones and electronic devices "out of sound and out of sight." Bluetooth speakers on a trail are the single fastest way to annoy the people around you, and they carry much farther on an open mesa than they seem to.

Headphones are a safety question as much as a courtesy one. Both earbuds in at full volume means you won't hear a bike coming up behind you on a multi-use trail, a rattlesnake, or someone calling "on your left." One earbud, or volume low enough to hear footsteps, solves it.

Group size matters too. OSMP asks large parties to break into groups of 16 or fewer, and a separate special-use permit is required for any passive recreational group activity with 25 or more participants. A wall of twelve people walking abreast is functionally a trail closure for everyone coming the other way.

Passing etiquette on the busy Chautauqua trails

The trails fanning out from Chautauqua Park, including the Chautauqua Trail, Bluebell-Baird, Royal Arch, and the Mesa Trail, absorb most of Boulder's weekend traffic. Etiquette that's optional on a quiet trail is essential here:

• Single file when anyone's coming. These trails are narrow and the vegetation beside them is the thing you're there to look at. Drop into a line rather than making people step off into the grass.
• Announce yourself early when passing. OSMP asks riders to alert others well in advance of their approach, and the same courtesy works on foot. A friendly "on your left" from ten feet back beats a silent pass at someone's elbow.
• Step aside on the durable spot. Rock, gravel, or bare dirt when you pull over, not the wildflowers. If there's no durable spot, hold your ground on the trail and let people squeeze past.
• Don't stop in the middle. Photo breaks, snack stops, and regrouping all belong off to the side at a wide spot, not on a switchback corner where people are climbing.
• Beat the crowd instead of fighting it. Chautauqua's lot fills very early on summer weekends, when paid parking is in effect and the free Park-to-Park shuttle runs from downtown. Our Boulder trailhead parking guide covers the options, and an early start solves the crowding and the afternoon storms at the same time.

The seven Leave No Trace principles, applied to Boulder

The seven principles come from the Leave No Trace Center for Outdoor Ethics, which is headquartered in Boulder. OSMP builds its own low-impact guidance on top of them. Here they are as the Center words them, with what each one looks like on a Boulder trail.

The 7 Principles of Leave No Trace are copyright the Leave No Trace Center for Outdoor Ethics and are reproduced here unaltered. Learn more at lnt.org.

Boulder rules that surprise visitors

A handful of OSMP regulations catch people out, and every one of them is enforceable by summons. Trailhead signs vary by area, so read them, but these apply broadly on City of Boulder open space:

• No drones. Operating a drone or any unmanned motorized vehicle is prohibited on OSMP land.
• No camping. Camping is prohibited on OSMP, along with tents and other structures. The one exception is the small Buckingham Campground at the Fourth of July Trailhead, about an hour west of town. See our Boulder camping guide for legal options.
• No alcohol, marijuana, or smoking. Open containers and consumption of alcohol are prohibited, public marijuana consumption is prohibited, city ordinance bans smoking on OSMP including e-cigarettes, and glass containers are prohibited.
• No racing. Competitive events are prohibited, defined as any activity where four or more people try to exceed each other's performance. A group time trial up Sanitas is technically a violation.
• Parking permits and curfews. Vehicles not registered in Boulder County need a daily ($5) or annual ($25) permit to park at some trailheads, and most OSMP lots close to vehicles between 11 p.m. and 5 a.m.

For what to actually carry on a Boulder trail, see what to bring hiking in Boulder, and the main Boulder hiking guide has the trails themselves.

Boulder trail etiquette: FAQ

Sources

Every rule on this page comes from these official sources. Regulations vary by area and change by season, so read the posted signs at the trailhead too:

• City of Boulder OSMP: Leave No Trace on OSMP (share our trails, stick to trail, mud, dog waste, leave it as you find it, devices, group size)
• City of Boulder OSMP: Biking on OSMP (yield rules, passing, speed, minimum-impact cycling)
• City of Boulder OSMP: Equestrians on OSMP (yielding to equestrians, riding through mud, HCA off-trail permits)
• City of Boulder: OSMP Rules and Regulations (drones, camping, alcohol and smoking, competitive events, dog waste, curfew)
• City of Boulder: Muddy Trail Closures (current closures and text alerts)
• City of Boulder: OSMP Permits (Off-Trail Permit Program, special use permits, parking permits)
• Leave No Trace Center for Outdoor Ethics: The 7 Principles