Anyone looking for waterbirds in Boulder County must make sure to check Boulder Reservoir, especially in autumn. The long list of rarities that have been found here in fall include Red-necked Grebe, Pacific Loon, Arctic Tern, Long-tailed Jaeger, and Ruff. More likely finds include Osprey, Bald Eagle, Forster’s Tern, and California Gull. Also consider visiting the adjacent Coot Lake for more viewing opportunities. Note: dogs are not allowed from May 15 – Labor Day. An entry fee is charged from April – October.
Flatirons
The Greatest Outdoors
Famous as a symbol of the 1960s counterculture, former home of the beat poets, and now a hub of the tech industry, the university town of Boulder lies right at the base of the Rocky Mountains proper. Thanks to decades of open space preservation and land conservation, the Boulder area is packed with places to view wildlife. The mountain parks host nesting falcons and Golden Eagles; the foothill trails run through territories of MacGillivray’s and Virginia’s Warblers; and the wetlands make good nesting grounds for Blue-winged and Cinnamon Teal. Boulderites love the outdoors more than almost anybody, and if you come to visit, you’ll immediately see why.
Admission: Daily entrance fee, April - October
Ownership: Municipal
Walden Ponds Wildlife Habitat and Sawhill Ponds
Admission: Free
Ownership: Walden - County, Sawhill - City
Doudy Draw and the South Mesa Trail
Admission: Free; there is a parking fee
Ownership: City of Boulder
Admission: State Parks Pass.
Ownership: Colorado Parks and Wildlife
Twin Lakes Open Space
These two lakes rarely attract many interesting waterbirds, but the trees around them can be great in spring migration for warblers, flycatchers, and other migrants. Interesting birds here have included Eastern Bluebird, Eastern Phoebe, Gray Flycatcher, and Northern Waterthrush. A well-known pair of Great Horned Owls nests in a hollow snag just across the creek from the path. In spring, when the young become visible in the nest, it is common to find a gaggle of owl-watchers blocking the trail. Note that West Lake is an off-leash dog park.
East Boulder Trail – Gunbarrel Farm/ White Rocks Trail
The open space and White Rocks Trailhead provide access to the same area from two different directions. In the north, the open land rises on a high prairie bluff and is one of the best places in the area to find nesting Grasshopper Sparrows in summer, along with the likes of Western Kingbird, Horned Lark, and Blue Grosbeak. Traveling south, the trail drops down to cross the creek, where Tree Swallow, Warbling Vireo, and Bullock’s Oriole nest. Near the White Rocks Trailhead, eastern birds like Orchard Oriole and Least Flycatcher have sometimes set up shop, alongside southwestern species such as Black-chinned Hummingbird and Bushtit. Please note: dogs are not allowed at the White Rocks Nature Preserve.
Boulder Creek & 75th Street
Located next to Walden Ponds and connected via footpath, the bridge over the creek here is a traditional nesting site for American Dipper, and Eastern Phoebe has also nested here in some recent years. The trees attract spring migrants, including vagrant warblers.
Walden Ponds Wildlife Habitat and Sawhill Ponds
Walden and Sawhill Ponds are some of the most important birding areas in Boulder. Between fall and spring, over two dozen ponds make this one of the best places in the area to look for dabbling and diving ducks, shorebirds, and the occasional vagrant, such as swans. March is the best month to catch migrating ducks. In summer, Wood Ducks nest along Boulder Creek, along with the occasional Eastern Screech-Owl; Bank Swallows flit overhead and Eastern Kingbirds twitter angrily. You might also view the Osprey nest, cormorants, bitterns, and a heron rookery. Near the parking lot for Walden Ponds, a boardwalk across Cottonwood Marsh provides up-close looks at Tree Swallows in nest boxes, and Red-winged Blackbirds on territory. Watch for garter snakes, frogs, and other critters along the edges of the ponds.
Teller Lake #5
This lake sits amidst farmland utilized for livestock grazing, crop production, and even beekeeping! The water sometimes attracts interesting waterbirds and Dickcissel has at times bred in the fields to the south. Lark Bunting and Blue Grosbeak have also been spotted here. The nearby black-tailed prairie-dog colonies are sure to attract raptors and other predators. Please note dogs are not allowed at this property.
Erie Lake and Thomas Reservoir
These small lakes are best known as places to find gulls in the colder months, when the water is partly frozen. They can also attract ducks and other waterbirds, and rarities have been found in the area; Erie Reservoir even once boasted a Yellow-billed Loon.
Waneka Lake/Greenlee Wildlife Preserve
This lake in the middle of a neighborhood in Lafayette is a great place to look for birds in all seasons, along with the adjacent Greenlee Wildlife Preserve. In summer, Pied-billed and Western Grebes can be found on the lake, and Swainson’s Hawk is easily seen. In migration, migrant warblers and thrushes skulk in the undergrowth. Concentrations of Barn Swallows in late fall can be very impressive. In winter, ducks, geese, and gulls can congregate here, and the flocks can include rarities, such as Barrow’s Goldeneye and others.
Valmont Reservoir complex
This complex of three reservoirs is an important birding spot in Boulder. In spring and fall migration, look for Western Grebes, Eared Grebes, and many ducks; Bald Eagle, Golden Eagle, and Ferruginous Hawk are also regularly seen hunting in the area. The reservoirs can be scanned at any time from Legion Park, where a scope is necessary. The area can also be accessed from the Open Space offices on the east side. When the gate is open, during business hours on weekdays, one can drive in, park at the Open Space offices, and walk west to the reservoirs, climbing the butte for the best view. Outside business hours, one can park outside the gate and walk a longer distance to the same destination.
Bobolink Trailhead
From late May through mid-July, the stars of the show along this trail are – you guessed it – Bobolinks! This is one of the few reliable nesting sites for the species along the Colorado Front Range. A nice riparian walk along South Boulder Creek provides viewing of some water and forest birds and adjacent tallgrass prairie provides habitat for grassland birds. Also watch for foxes and coyotes in the fields.
Baseline Reservoir
This private lake is a good place to look for migrating loons and diving ducks, including scoters, in late fall. Sometimes gulls roost on the southwest shore, near the road, where they are easily viewed. In winter, if the water is open, you may see some rare birds on the lake. The easiest viewing of the reservoir is on the southwest side, off Cherryvale’s wide shoulder. Please watch for traffic.
Doudy Draw and the South Mesa Trail
These open space trailheads near Eldorado Springs provide access to miles of hiking trails and some riparian habitat along the creek. Look for Spotted Towhee, Yellow-breasted Chat, Blue Grosbeak, and Blue-gray Gnatcatcher in dense scrub, as well as the occasional Red-eyed Vireo in taller trees. Lazuli Bunting is common in summer; Indigo Bunting and hybrids are uncommon to rare. Keep an eye out for herds of mule deer and elk along the trails. For a first-class birdwatching destination, follow the South Mesa Trail to the Towhee Mesa Loop/Towhee Homestead Loop, which includes rich grasslands, forest communities, and lots of shrubby drainages. A side trip along the Upper Big Bluestem Trail is also great for birds. Note: there is a fee to park at this property.
Eldorado Canyon State Park
Driving into Eldorado Canyon, you will be rewarded with spectacular views of enormous cliffs where Canyon Wrens, White-throated Swifts, and Violet-green Swallows nest. World-renowned as a premier rock climbing destination, it’s hard not to spend a little time also watching the brave climbers scaling Eldo’s dramatic sandstone cliffs!
South Boulder Creek carves a path through the canyon, providing potential for seeing American Dipper in the rushing stream. Farther inside the park, the landscape flattens and an extensive trail system begins, providing access to mixed conifer forest with typical foothills species ranging from Western Tanager to the striking Abert’s squirrel. Other birds of interest you could possibly spot here include: Lewis’s Woodpecker, Prairie Falcon, Golden Eagle, Virginia Warbler, and Chestnut-sided Warbler. A State Parks pass is required for entry. Hunting occurs at the Crescent Meadows portion of the park, so be sure to check for seasonal restrictions before visiting that section.
Lower Bear Canyon Trail
This easy trail leaves a neighborhood and parallels a shrub-filled drainage up into the ponderosa pines. Look for Bushtit, Spotted Towhee, and both Blue and Steller’s Jay. It is good place to see migrant birds in late spring, and Virginia’s and MacGillivray’s Warbler in summer.
Gregory Canyon
One of the finest birding areas in Boulder, Gregory Canyon is on the edge of the city, where the foothills begin. The thick riparian tangles here support species, including Warbling Vireo, Gray Catbird, Virginia’s and MacGillivray’s Warblers, and Yellow-breasted Chat. The surrounding pine forest add Lesser Goldfinch, three species of Empidonax flycatcher, Black-headed Grosbeak, and Western Tanager. The cliffs overhead are home to Canyon Wrens and a few pairs of Peregrine and Prairie Falcons. Arrive very early at this popular park in order to secure a parking spot. Note: there is a fee to park at this property.
Boulder Creek (downtown section)
A paved walking and biking trail follows Boulder Creek through much of the city of Boulder. Along the way, it is often canopied by mature cottonwoods and willows, making it a good birding destination. Birds that breed here include White-breasted Nuthatch, Warbling Vireo, and the rare Eastern Screech-Owl. Migrants can pass through in good numbers in spring and fall and American Dipper can be found along the creek, especially in winter. Be sure to stop for a refreshment on one of the many outdoor patios in downtown Boulder, where you can enjoy birding with a cold brew!
Wonderland Lake
Nestled in a scenic neighborhood in north Boulder, this area offers open space, short and easy trails, and water access that attracts a diversity of waterfowl. Trails leading away from the lake cross foothills grassland and tallgrass prairie stands, providing plenty of habitat for a variety of birds.
Betasso Preserve
This popular park west of Boulder, with miles of trail through meadows and pine savannahs, is a great place to find specialty species of the ponderosa belt, including Mountain and Western Bluebirds, Pygmy Nuthatch, Wild Turkey, and the tufted-eared Abert’s squirrel.
Walker Ranch Open Space
This open space in the foothills above Boulder is a good place to find low-elevation mountain species like Pygmy Nuthatch, Mountain Chickadee, Mountain Bluebird, and both sapsuckers. In winter, you can find flocks of Dark-eyed Juncos, including all five Colorado subspecies. Keep your eye to the sky, as Golden Eagles sometimes fly over the mountain. Black Bears and Mountain Lions are also found in this area. Be sure to stop by the Flagstaff Nature Center at the summit of Flagstaff Mountain Road.