Nature on OSMP

Hike of the Month - Green Mountain

The summit of Green Mountain is a wonderful place to spend a warm June day. At 8,144 feet, it's high enough to feel cool even when it gets hot below. Spring flowers that have finished blooming at lower elevations may still be found on its forested trails. The area around the summit is often a haven for many butterflies: golden-brown fritillaries, huge black and yellow swallowtails, diminutive blues and hairstreaks. Climb to the top of the large boulder that marks the summit for a breath-taking view of the Indian Peaks, which are still dappled with snow. A peak finder at the top will help you identify various geographical features. You can reach Green Mountain Summit via various trails, depending on your desire for exercise. If you start at Gregory Canyon trailhead or Chautauqua Meadow, be prepared for a hard climb. You can drive to Realization Point and follow the Ranger Trail, which lets your car do much of the climbing for you. Or drive farther up Flagstaff Road to the Green Mountain West Ridge trail, which gets most of the elevation out of the way.

All trails to Green Mountain pass through the Western Mountain Parks Habitat Conservation Area (HCA), a unique place that preserves many rare plants and animals. If you wish to leave designated trails in the HCA, you must obtain an off-trail permit.

Learn about the the various Habitat Conservation Areas and the amazing flora and fauna they protect.

Summer Solstice - the Longest Day

In 2025, summer officially starts on June 20 at 8:41 p.m. MDT. The summer solstice for the northern hemisphere occurs when the sun is at its highest point in the sky around noon. It is about 23.5 degrees north of the celestial equator. If you were standing on the Tropic of Cancer, the sun would appear to be directly overhead at midday, and you would barely cast any shadow. Daytime is near its longest and nighttime near its shortest.

In the southern hemisphere, seasons are reversed. The June solstice marks the beginning of winter, and the sun is at its lowest point in the sky around noon, appearing in the northern sky instead of the southern! People in the southern hemisphere experience their longest night.

Going Native

Gardening with Boulder's native wildflowers and shrubs is a rewarding activity that also helps our local ecosystems and wildlife. Learn how to garden with Boulder's native wildflowers. There are many local species that make fine additions to your yard: ground cover, large blossoms, shrubs and trees. They have been growing in this climate untended for thousands of years, so they easily shrug off the worst weather Boulder can dish up. Drought? No problem. OSMP staff who have gone native in their own gardens have created an extensive plant list for you, with species-specific growing tips. Dare to go native.

Bat Maternity Month

OSMP is home to many species of bats, including the vanishing Fringed Myotis and Towsend's Big-eared Bats. During June, females of these two species gather in maternity colonies in caves or under rock overhangs to rear their babies in a communal nursery. Two of the eleven known maternity colonies of Townsend's Bats in Colorado are found on OSMP. Often mistaken for rodents, bats are not nearly as prolific. A female will give birth to only one pup each year, rarely twins. They invest a great deal of care in their baby: mom leaves the communal roost each evening to hunt mosquitoes and other night-flying insects, and returns to nurse the pup. Mothers will stay with their pup all summer, then spend the winter in hibernation. Known maternity colonies on OSMP are protected by wildlife closures, but you can enjoy watching bats fly in the darkening sky of early dusk.

Birds at the Crossroads

Have you noticed flocks of fast-flying birds zipping, zooming and diving around street intersections? They are swallows, searching for insects attracted by artificial lighting. You may see any of four common types of swallows around Boulder: Barn Swallows, which are a pale orange underneath and have a forked tail; Tree Swallows which are white underneath and dark green on top; Violet-green Swallows, which are similar to Tree Swallows in appearance but have two white patches on their lower back; and Cliff Swallows, dark blunt-tailed little birds with patches of buff and reddish-brown. All swallows have long, pointed wings for fast, maneuverable flight. They snap up insects on the wing. Swallow parents share nesting duties, and will bring a compressed ball of insects to the nestlings 400 times a day! That's a lot of bugs that otherwise might be bugging you. When weather gets cold and bugs stop flying, swallows will migrate south in search of other insects to eat.

June is for Warm Season Grasses

Grasses in Colorado fit one of two life styles: cool or warm season growth. Most introduced European grasses green up quickly during the cool months of spring and bloom in May or June; examples are Smooth Brome, Orchard Grass or noxiously aggressive Cheat Grass. Most grasses native to Colorado wait for the warm season: they begin their growth spurt in June and grow and flower in July and August, when Colorado is hot and dry. Some gardeners take advantage of this by planting short native lawn grasses such as Buffalo Grass and Blue Grama, which grow well without extra water during the hot months and require less mowing. Other lovely native warm season grasses include Big Bluestem, Little Bluestem and Prairie Cord Grass.

So what does a grass flower look like? Tiny greenish or yellowish spikes on a tall stalk. Most grasses are pollinated by wind, so they do not invest energy in large showy flowers with nectar and perfume -- strategies used by other plants to lure pollinating insects. To be carried by wind, grass pollen grains must be very tiny. The fine pollen of grasses and other wind pollinated plants, such as ragweed, pines and other conifers, cause most pollen allergies.

The Last Word

Happiness is a butterfly, which when pursued, is always just beyond your grasp, but which, if you will sit down quietly, may alight upon you.

~Nathaniel Hawthorne