The best bike rides in Boulder, Colorado come with a reputation to live up to. Pro teams train on the canyon climbs above town, the Coors Classic once made these roads famous coast to coast, and the city has built enough separated path that you can circle the whole place without ever fighting car traffic. Boulder takes cycling about as seriously as any town in America. This is a local's rundown of where to actually ride: road, gravel, and dirt, checked against current conditions so you're not chasing a route that washed out in a flood or a trailhead that's still under construction.
The road climbs
If you only do one climb here, it's Flagstaff. It's the test piece every visiting rider wants to tick off, and it earns the hype. From the corner of Broadway and Baseline up to the amphitheater turnaround it runs 5.9 miles and 2,204 feet of gain, averaging around 7 percent, with a max near 15 and short pitches kicking to 18. Measured from the base of Baseline instead, it's a shorter and steeper 4.55 miles at 8.5 percent, so don't be surprised when different apps quote you different numbers. If that isn't enough suffering, the Super Flag extension tacks on roughly two more miles, most of it over 10 percent, climbing to the mailboxes near 8,000 feet.
North of town, the Lee Hill and Olde Stage loop is the classic warmup that isn't really a warmup. It's about 20.8 miles with roughly 2,180 feet of climbing, and the Lee Hill Drive pitch alone is 4.3 miles at 5.9 percent. For a bigger day, point yourself up Lefthand Canyon toward Ward: 16.7 miles and 3,686 feet at a steady 4.2 percent, with the steepest 1.6-mile section hitting 8.5 percent near the Sawmill Road junction. That road was destroyed in the 2013 flood, but the rebuild and repave were finished back in fall 2016, and it's open, no closures listed on Lefthand Canyon, Lee Hill, or Olde Stage as of this writing.
Then there's the Morgul-Bismark, the 13.1-mile loop around Superior that carries Boulder County cycling history on its back. This is where the Red Zinger and the Coors International Bicycle Classic raced (the Coors event folded in 1988, with LeMond and Hinault among those who rode it), and it's where the opening race scene of American Flyers was shot in 1985. The infamous "Wall" is a one-mile ramp reaching about 18 percent near the McCaslin and CO 128 corner. Fair warning: suburban development has changed the original course, modern race versions use a modified circuit of about seven miles, but the full loop is still rideable and Superior has added bike lanes along the way.
Got legs and a full day? The Peak to Peak Highway is the big one. It's a 55-mile National Forest Scenic Byway, designated in 1918 and the oldest byway in Colorado, running from the Estes Park area down to I-70 through Allenspark and Nederland. Ridden end to end it's about 60 miles one-way with a little over 5,000 feet of climbing. It connects naturally to the top of the Lefthand-to-Ward grind, which is how a lot of locals string a huge canyon day together.
Gravel and dirt roads
Boulder's gravel scene is as good as its pavement, and you don't have to drive anywhere to find it. South of town, the Marshall Mesa network on city open space links Community Ditch, Coal Seam, Greenbelt Plateau, Marshall Valley, and Cowdrey Draw into the ride everyone calls the "Dirty Bismark," the roughly 15-mile gravel cousin of the Morgul loop. Bikes are allowed on those trails, and Class 1 and 2 e-bikes are permitted on the same ones (Community Ditch east of Highway 93). Good timing, too: the Marshall Mesa Trailhead reopened on March 27, 2026 after a full reconstruction, so parking and access are fresh.
North of Boulder is Roubaix country. The dirt roads that connect Nelson Road to St. Vrain Road, 39th, 49th, and 51st Streets, plus Crane Hollow Road linking Hygiene Road to St. Vrain, make up the course of the Boulder Roubaix. It's Colorado's oldest one-day race, first run in 1992, and the 2026 edition rolled a new 30-mile circuit that was about 60 percent dirt, including gravel across the Boulder Reservoir dams. You can ride the loop any day you like; it's public road, just quiet and washboarded in the best way.
Mountain biking
The close-in classic is Betasso Preserve, and it comes with one rule you absolutely have to know: bikes are prohibited on the Canyon Loop (3.3 miles) and the Benjamin Loop (2.4 miles) every Wednesday and Saturday. The Betasso Link (1.3 miles) stays open to bikes all week, but no e-bikes there year-round. The county posts fixed directions of travel, Canyon Loop counterclockwise, Benjamin clockwise, so read the signs at the trailhead rather than trusting an old blog. It's open sunrise to sunset.
Heil Valley Ranch is fully back after the October 2020 Cal-Wood Fire, which closed the south side for 607 days before it reopened in June 2021. The Wapiti Trail was permanently rerouted around a golden-eagle nest, and the new route opened in June 2024. The current lineup open to bikes: Picture Rock at 5.2 miles (the standout descent), Wapiti at 3.0 miles, Ponderosa Loop at 2.6, and Overland Loop at 2.3 (counterclockwise for bikes). No e-bikes, no dogs, sunrise to sunset. One real hazard to respect: this is burn-scar terrain, and wind can drop dead trees across the trail, so stay on it and keep your eyes up.
Walker Ranch is the advanced loop, about seven miles up Flagstaff Road from town. It's a 7.8-mile loop with roughly 1,600 feet of climbing and descending, technical rock gardens, staircases, and a mandatory hike-a-bike section, so it earns its intermediate-to-advanced billing. The trailhead has around 46 parking spots and restrooms, and it runs sunrise to sunset. For something completely different, Valmont Bike Park is 42 acres of city-run jumps, pump tracks, and skills lines inside Valmont City Park. Individual admission is free, it's open 5 a.m. to 11 p.m. daily (sunrise to sunset is the smart window), Class 1 and 2 e-bikes are allowed, and it closes during freeze-thaw and wet weather to protect the dirt features, so check the notices before you load up.
Paths and practicalities
You can ride Boulder without touching a busy road, and the signed B360 loop proves it: 24 miles of paths and lanes circling the entire city, with a shorter B180 variant, both starting and ending at Valmont Bike Park. Green and blue route markers make it self-guided year-round, and Community Cycles runs a group version each June during Walk & Bike Month. The spine of the whole system is the Boulder Creek Path, 5.5 official miles from Boulder Canyon on the west to the Stazio Ballfields past 55th Street on the east. City rules apply: 15 mph speed limit, keep right and pass left with an audible signal, yield to pedestrians, lights at night, and Class 1 and 2 e-bikes are fine while Class 3 is prohibited on all city multi-use paths.
For getting out of town under your own power, the protected US 36 Bikeway runs the commuter corridor toward Denver (it was completed in 2016, connecting Boulder toward Westminster). Riding Highway 36 north to Lyons is a beloved 16-mile rite with a wide shoulder in most sections, but it carries fast traffic and a reputation as one of the county's deadliest roads, so ride it with respect. A separated Boulder-to-Lyons bikeway has been in active planning as of mid-2026, but it is planned, not built, so don't expect a protected lane out there yet.
Visiting without a bike? Boulder BCycle runs a station-based e-bike share with roughly 55 docking stations, covering a service area running about Iris to Baseline and Broadway to 55th, with pedal-assist up to 17 mph. Current pricing runs $7.63 for a single 30-minute ride, $18.60 for a 24-hour guest pass, $32.71 monthly, and $163.57 annual, with $7.63 for each extra 30 minutes; there's a $40 low-income annual option too. The city ran a competitive procurement in early 2026 and intends to award BCycle a renewed contract in mid-2026, so the program is continuing, though it's worth a quick re-check on pricing before you commit. When the ride's done, our brewery guide handles the recovery protocol, and if you'd rather trade the saddle for boots, our best hikes guide covers the same foothills on foot. Bike shops, rentals, and repair are in the business directory.
Frequently asked questions
How hard is the Flagstaff climb in Boulder?
It's a genuine challenge but very doable for a fit rider. From Broadway and Baseline to the amphitheater it's 5.9 miles and 2,204 feet of gain at around 7 percent, with short pitches near 18 percent. Measured from the base of Baseline it's steeper, 4.55 miles at about 8.5 percent, and the Super Flag extension adds roughly two more miles over 10 percent if you want more.
Can you ride a bike around all of Boulder without using busy roads?
Mostly, yes. The signed B360 loop circles the entire city over 24 miles of paths and lanes (with a shorter B180 option), both starting at Valmont Bike Park. The Boulder Creek Path also runs 5.5 miles straight through the middle of town, so you can connect a lot of the city car-free.
Are e-bikes allowed on Boulder's trails and paths?
It depends on the class and the location. Class 1 and 2 e-bikes are allowed on city multi-use paths like the Boulder Creek Path and at Valmont Bike Park, while Class 3 e-bikes are prohibited on all city multi-use paths. Betasso Preserve's Link trail bans e-bikes year-round, and Heil Valley Ranch allows no e-bikes at all, so check each area's rules.
When are bikes not allowed at Betasso Preserve?
Bikes are prohibited on Betasso's Canyon Loop and Benjamin Loop every Wednesday and Saturday. The Betasso Link trail stays open to bikes all week, but no e-bikes on it. The preserve is open sunrise to sunset, and the county posts fixed directions of travel, so follow the signs.
Is the road to Lyons safe to bike?
It's a popular 16-mile ride with a wide shoulder in most sections, but Highway 36 to Lyons carries fast traffic and is considered one of the county's deadliest roads, so ride it carefully. A separated Boulder-to-Lyons bikeway has been in planning as of mid-2026, but it hasn't been built yet.
Where can I rent a bike in Boulder as a visitor?
Boulder BCycle offers station-based e-bike share with roughly 55 docking stations across a service area running about Iris to Baseline and Broadway to 55th. A single 30-minute ride is $7.63 and a 24-hour guest pass is $18.60, with pedal-assist up to 17 mph. Pricing is worth re-checking, since the city intends to award a renewed contract in mid-2026.
