Sep 3, 2026

Boulder's Seasonal Dog Leash Restrictions: Birds, Then Bears

Two windows, two animals, and only two weeks in August with neither in force. Plus the month-long disagreement between the city's trail table and its own news release.

Luis ZamoraCo-founder of PetCompass; Dog Dad to Banzo and Tuck

Boulder, Colorado10 min readThings to Do

Boulder suspends off-leash privileges twice a year, on named trails, for two different animals. One window protects ground-nesting birds. The other protects bears fattening up for winter.

Verbatim from the Dogs on OSMP page:

"Seasonal Leash restrictions are in place May 1 - July 31 & Aug. 15 - Dec. 1 on some trails to protect ground-nesting birds and bears."

Which leaves two open windows: August 1 to 14, and December 2 to April 30. Everything else is a seasonal restriction somewhere in the system.

And there is a date conflict in the city's own publications, which we set out below rather than resolving.

Window one: ground-nesting birds, May 1 to July 31

Three months in late spring and early summer, applied trail by trail with a label the city calls Grassland Bird.

From the trail regulations table, verbatim examples:

Trail	Grassland bird restriction as published
North Sky	"Grassland Bird, No Dogs May 1 to July 31"
Vesper	"On-Corridor Voice and Sight. Grassland Bird, Leash Required May 1 to July 31"
East Boulder - Gunbarrel	"Grassland Bird, Leash Required May 1 to July 31 from Boulderado access to White Rocks junction"
Greenbelt Plateau	"Seasonal leash restriction: leash required south of the 90 degree turn in the trail May 1 to July 31"

Note that North Sky goes further than a lead. For those three months it is No Dogs, not leash required. A trail you walked in April with a dog is closed to dogs in May.

And note the partial-trail restrictions. East Boulder Gunbarrel is leash-required only between two named points, and Greenbelt Plateau only south of a bend in the trail. Signage is the operative instruction on the ground.

Window two: bears, August 15 to either November 1 or December 1

This is the one with the conflict, and it is worth knowing about before you plan an autumn hike.

The current news release says December 1. Verbatim from the city's August 2026 announcement: "The on-leash requirement will be in effect through Tuesday, Dec. 1".

The Dogs on OSMP page also says December 1, in the sentence quoted at the top of this guide.

The trail regulations table says November 1. Verbatim on Amphitheater: "Seasonal leash restriction: leash required Aug. 15 - Nov. 1." The same November 1 date appears on Amphitheater Express, Bluebell Baird, Doudy Draw, Gregory Canyon, Ranger and Saddle Rock rows.

A month apart, on the city's own website, on the same restriction.

We are not going to pick one. Assume the longer window, through December 1, and follow the signs at the trailhead, because signage is what an enforcement officer will point at and because the news release is the more recently dated of the two.

The four areas named in the release

Verbatim: "The on-leash requirement will be in effect through Tuesday, Dec. 1 , in the following City of Boulder Open Space and Mountain Parks areas :"

"Portions of Gregory Canyon, Saddle Rock, Amphitheater and Bluebell-Baird Trails" "Skunk Canyon up to the Mesa Trail" "Shadow Canyon South from the Mesa Trail up to the intersection with Shadow Canyon North" "The upper part of the Doudy Draw Trail above Springbrook Loop"

The same four areas appear in the city's 2024, 2025 and 2026 releases. That is a three-year pattern, which makes it reasonable to plan around, though the city renews it annually rather than fixing it in a calendar.

One word that changed in 2026

The 2026 release is more specific than its predecessor about what tag holders must do. Verbatim:

"While visitors registered in the Voice and Sight Tag program may walk their dogs off-leash on many OSMP trails as part of the city's Voice and Sight Tag Program, the city reminds tag holders that all dogs are required to be on a handheld leash during this critical foraging window to help prevent dog-wildlife encounters."

"Handheld leash." The 2025 version of the same release asked visitors "to always leash their dogs in the presence of wildlife" without specifying how the lead is held.

Why the bear window exists

Verbatim from the release: "City-managed open space and natural areas provide important habitat for black bears. The dog leash requirement is intended to minimize dog-bear encounters where high-quality bear foraging habitat is near trails. It is timed to coincide when bears begin to consume large amounts of food on open space to gain enough weight to support them through their long winter hibernation."

A feeding bear is a stationary bear, close to trails, eating for hours. That is a different encounter from a bear crossing a path.

The city adds a point about what happens to bears that come into town, verbatim: "Community members are also encouraged to help protect bears by ensuring trash containers are locked, because bears that come into town for food and find it are more likely to stay. If they stay, bears are at risk of being killed for a number of reasons, including being hit by vehicles, being electrocuted by power poles, ingesting harmful chemicals and losing their natural fear of people, which may result in euthanasia by wildlife officers ."

What to do if you meet a bear with a dog on the lead

Verbatim from the same release:

"Stay calm." "Keep your distance. Back slowly away, facing the bear. Avoid direct eye contact." "Slowly and calmly leave the area. Talk aloud so the bear will become aware of you." "Fight back if attacked. Black bears have been driven away when people fight with rocks, sticks, binoculars or bare hands."

And the recommendation that goes beyond the restricted trails, verbatim: "Consider putting your dog on a leash during active bear season on all trails for your dog's protection."

All trails, not just the four named areas. That is the city's own advice, and our dogs and wildlife in Boulder guide covers the bear and mountain lion guidance in full.

How the seasons interact with your tag

A Voice and Sight tag does not override a seasonal restriction. The programme's own page is explicit, verbatim: "All trails posted as requiring a leash prohibit the use of voice and sight control."

So during a seasonal window, the affected trails are leash-only for every dog, tagged or not. Our Voice and Sight Tag Program guide covers what the tag does buy, and note that the penalty ladder for off-leash violations starts at a maximum of $100 and reaches a floor of $300 for a third offence in 24 months.

The four regimes that apply outside the seasonal windows are set out in our dogs on OSMP trails guide, including the 20-foot corridor rule and the trails closed to dogs year-round.

A twelve-month planner

January to April. No seasonal restriction published. Full regime map applies, so check the trail's own label.

May 1 to July 31. Grassland bird season. Leash required on named segments, and North Sky is closed to dogs entirely. Ground-nesting birds are the reason a dog twenty feet off the trail matters here.

August 1 to 14. The gap. Two weeks with neither window in force.

August 15 to December 1. Bear foraging season on the four named areas, with the caveat that the trail table says November 1. Handheld leash for tag holders.

December 2 onward. Restrictions lift, and the city's winter advice takes over: frostbite on paws, tails and ears, ice on ponds, and salt on the pavements. Our cold weather pet safety guide covers that ground.

Every month: the Trailhead Leash Program applies at every OSMP trailhead regardless of season, and waste must be carried out rather than staged beside the trail.

If a seasonal restriction has closed the walk you planned, our Boulder dog licence guide is a reminder that the city licence tag is required whatever the season, and our emergency vets in Boulder guide is the one to have saved before an autumn hike goes wrong a mile from the trailhead.

What the restrictions are actually protecting

Two very different animals, and knowing which one explains why the rules differ in kind.

Ground-nesting birds, May to July. The nests are on the ground, in grass, often within a few feet of a trail. A dog twenty feet off the path is not a nuisance in that setting, it is a direct risk to a clutch of eggs or flightless chicks. That is why the bird-season restriction sometimes escalates past a lead to No Dogs, as it does on North Sky, and why it is applied to specific segments rather than whole trails.

Black bears, August onward. Verbatim from the city's bear and mountain lion page: "Wildlife scientists estimate that Colorado could hold about 12,000 black bears and zero grizzly bears." And a detail worth knowing before you identify one at distance, verbatim: "All bears in the Boulder area are American black bears, even though some may not have black fur. It's not unusual for black bears to possess brown, cinnamon-colored or even blond fur!"

The risk in bear season runs both ways. A dog that chases a bear can bring it back to you, and a dog off lead near a feeding bear is a dog making its own decisions about a 200-pound animal with cubs nearby.

The same page carries the year-round instruction that makes the seasonal rule easier to remember, verbatim: "Keep dogs on leash, especially near streams."

Mountain lions are the quieter risk, and they are not seasonal. Verbatim: "Keep pets under control. Roaming pets are easy prey and can attract lions." The city also puts the odds in perspective, verbatim: "The chances of seeing a lion are slight, and even less likely is an attack by a mountain lion."

Where to check before you go

The interactive dog regulations map, which the city links from its Dogs on OSMP page and updates with trail closures.

The trail regulations table, which carries the per-trail label and the seasonal note.

The signage at the trailhead, which is the version that settles a disagreement between two city pages.

And the city's news page during August, since the bear restriction is announced annually rather than being a fixed calendar rule.

If a seasonal closure has taken your usual route, our Boulder dog parks guide covers the four fenced and off-leash sites inside the city, and our dogs on Boulder County open space guide covers the separate county system, which has its own list of properties where dogs are not allowed at all.

Frequently asked questions

When are Boulder's seasonal dog leash restrictions in force? The city states that seasonal leash restrictions are in place May 1 to July 31 and August 15 to December 1 on some trails, to protect ground-nesting birds and bears.

Does the bear restriction end November 1 or December 1? The city's own pages disagree. Its trail regulations table says August 15 to November 1 on the affected trails, while the Dogs on OSMP page and the August 2026 news release both say through December 1. Assume the longer window and follow posted signs.

Which trails have the bear-season leash requirement? The 2026 release names portions of Gregory Canyon, Saddle Rock, Amphitheater and Bluebell-Baird Trails, Skunk Canyon up to the Mesa Trail, Shadow Canyon South from the Mesa Trail to the intersection with Shadow Canyon North, and the upper part of the Doudy Draw Trail above Springbrook Loop.

Are any trails closed to dogs during bird season? Yes. North Sky is listed as No Dogs from May 1 to July 31, while other trails such as Vesper and parts of East Boulder Gunbarrel and Greenbelt Plateau become leash required.

Does my Voice and Sight tag still work during a seasonal restriction? No. The city states that all trails posted as requiring a leash prohibit the use of voice and sight control, so affected trails are leash-only for every dog.

What kind of leash is required in bear season? The city's 2026 release states that all dogs are required to be on a handheld leash during the critical foraging window.

Sources

Seasonal dates are announced annually and two city pages currently disagree. Check the trailhead signage before you rely on either.