Home to the tallest sand dunes in North America and the largest archeological preserve in the USA, Colorado's national parks are grand in every way.
As the USA's National Park Service celebrates its centenary, we're profiling the wilderness areas it manages.
Today: The national parks of Colorado . . .
Black Canyon of the Gunnison National Park
"An eye-popping chasm."
- J. Carlson and D. Noe, in the Colorado Geological Survey's 'Rock Talk' newsletter
Because this canyon is so deep and narrow, it's often described as a gash or slit in the earth that allows sunlight to fully reach the bottom only at midday.
The Park Service calls this protected area of Southwest Colorado (425 kilometres from Denver) a "vertical wilderness," with some of the steepest cliffs, oldest rocks and craggiest spires in North America. The Park Service says the gorge reaches a depth of 829 metres. Its narrowest point is 12 metres.
Park visitors may hike, drive and camp. Trails range from easy to strenuous. However, climbing here is for highly experienced experts only.
Driving routes also provide access to views of the chasm.
The 11.3km South Rim Drive has 12 outlooks, most reached by walking a short trail. North Rim access is via a gravel road that includes six outlooks and some of the park's most impressive views. The East Portal Road into the Curecanti National Recreation Area provides river access.
Founded: National monument, 1933; national park, 1999
Attendance: 209,166 (2015)
Great Sand Dunes National Park
"A sandbox of epic proportions."
The tallest sand dunes in North America don't border an ocean or lake, although the 78-square-kilometre sand-dune field here was once a lake. Instead of the expected beach and surf, these massive, windswept mounds are surrounded by alpine peaks, a desert valley, creeks, mountains and rural range land in Southern Colorado. Atop the tallest dune (230km from base to crest), the nearest city, Albuquerque, feels more distant than 396km.
Today, on land once roamed by Stone Age people hunting with large stone spears or dart points, park visitors may hike, sand board, sled, splash in Medano Creek or simply wander. (Just note that summertime sand surface temperatures can top 65.5 degrees.)
Tourists here also may do what the early nomads likely did in this place: look at the night sky. During a full moon, sky watchers may experience the view and move about without need for a flashlight.
Size: 148,988 acres (park and preserve)
Founded: National monument, 1932; national park and preserve, 2004
Attendance: 299,513 (2015)
Mesa Verde National Park
"From the rim of the [canyon] we had our first view of Cliff Palace. . . . To me, this is the grandest view of all among the ancient ruins of the Southwest."
- Charlie Mason, co-discoverer, in 'Mesa Verde National Park: Shadows of the Centuries', by Duane A. Smith
Ancient Pueblos built dense and intricate dwellings on this plateau near the modern-day Four Corners junction, where the states of Colorado, Utah, Arizona and New Mexico meet. Just the name Cliff Palace is intriguing enough to inspire interest in this largest archeological preserve in the country.
Protected in this park — also a Unesco World Heritage site, established by President Theodore Roosevelt as the first to "preserve the works of man" — are 600 cliff dwellings and 4300 archeological sites from ancestral Pueblo culture, which endured from AD 600 to 1300.
Cliff Palace, the most famous of the structures, has 150 rooms and 23 kivas, which are rooms dedicated to ritual and cultural activities. Park visitors may take guided and self-guided tours.
A 9.7km driving tour of the park takes in a dozen easily accessible sites.
Attendance: 547,325 (2015)
Rocky Mountain National Park
"The raw beauty of the rugged mountains contrasts with the calm loveliness of wildflower gardens growing nearby."
- The Park Service's 'Natural History Handbook Number Three' (1954)
It's no surprise that the Who's I Can See for Miles was on the Easy Rider movie soundtrack. It's an apt road-trip song about the vistas travellers seek. Here, park visitors can appreciate those lyrics by driving the highest paved road in the Park Service. Trail Ridge Road crests at 3713 metres. It's designated as an American Byway and All-American Road.
The park's panoramas also include two bodies of water named on the Wilderness Society's list of prettiest lakes in wild lands: Mills Lake, which offers high-elevation views of Longs Peak and the Keyboard of the Winds (spires that channel wind into unearthly sounds); and Loch Lake, with views of mountain peaks and Glacier Gorge.
Here in north-central Colorado, holidaymakers may access 563km of trails designed for all levels of ability. Hikers can walk valleys and meadows that were trod by native Utes until the late 1700s. Its later visitors included gold miners, followed by homesteaders and sightseers drawn to the lush environment.
Today, the Park Service says the landscape is home to a large variety of animal dwellers, including 60 species of mammals and 270 bird species. The park, which straddles the Western Continental Divide, also has 141 confirmed species of butterflies.
Size: 265,795 acres
Attendance: 4,155,916 (2015)