One river and two billion years created one of the most impressive canyons in the United States, a showcase of geologic time, and home to a fantastic National Park named for the feature dominating the surrounding landscape.
The Black Canyon, a dark and shadowy abyss cut by the Gunnison River, was first designated a National Monument in 1933, and later a National Park in 1999. Containing the most dramatic and deepest 19 km of the entire 77 km long canyon cut by the river, it is a natural wonder like none other, and Colorado’s own Grand Canyon.
It is one of the deepest and steepest in all of North America, dropping 829 m from Warner Point. At The Narrows, it is only 12 meters wide at river level and up on the rim at Chasm View, 335 meters. Throughout the entire length of the canyon, the average descent for the river is 8 m/km, and the most extreme again at Chasm View, where the river cascades 45 meters over one kilometre.
The extremes permit an average of only 30 minutes of sunlight in a day, and some parts never see any light, especially during the winter months. These conditions enable the Black Canyon to host its own weather, unique environments and ecosystems, most obvious in the opposing walls. The north side tends toward much less vegetation and craggy walls, while the south side has much more vegetation on a slightly gentler slope, but not by much. The canyon remains an obstacle, regardless of the approach.
As with most obstacles, many perceive it only a greater challenge than their last. Hiking opportunities abound in this National Park, though most choose the less confrontational auto tour. The routes offer some great short hikes right out to the edge. Most have guard rails, but some do not, so take caution.
There are two auto tours, one for the south rim, and another for the north; neither travel close enough to the rim to enable viewing of the entire canyon from the comfort of your vehicle. The south rim is the most popular, but to get the full impact requires getting out of the car, at minimum; otherwise, just a short walk along sometimes paved or hard packed trails.
Meandering relatively close to the edge of the immense canyon on either side, both routes close to vehicular traffic during winter months. The road into the South Rim The Visitor Center at Gunnison Point is still accessible year round, as are all other pedestrian activities.
Along the north rim, only a few steps take you to the edge of the canyon, while the along the south rim, one generally has to hike a few hundred yards; both sides are flanked at either end by extensive trails that lead to unique views of the canyon and surrounding countryside. It is also the location of the two campgrounds within the park.
Entering the park from the south, the first that one encounters is Rim Rock Trail. It follows a relatively flat and easy 0.8 km path away from the South Rim Campground, along the rim of the canyon through Tomichi Point overlook, and then on to the South Rim Visitor Center and Gunnison Point.
One can easily connect with the 3.2 km round trip Oak Flat Trail loop from the visitor center, which wanders through a thicket of Gambel Oak to some rocky outcrops with fantastic views, before ascending back up through a forest of Douglas Fir and Aspen. At a point where the trail wanders back near South Rim Road, a bypass cuts over to the road for easy access to the Uplands Trail, skirting Jones Summit and returning to the Rim Rock Trailhead.
At the end of South Rim Road another trail leads to one of the more spectacular views in the park, Warner Point. The 2.4 km round trip starts at High Point Overlook and wanders out to the edge of the canyon, through mountain mahogany, pinyon pines, and juniper. This is probably the best view in the entire park, with the Gunnison River far below, the San Juan Mountains and Uncompahgre Valley visible to the south, and the West Elk Mountains to the north.
Over on the north rim, the 11.2 km round trip North Vista Trail heads out to Green Mountain through sage, oak brush, then up into the pinyon pines and juniper forests, with multiple overlooks along the way. There is also a diversion over to Exclamation Point, which is only a 4.8 km round trip, for those uninterested in making the long journey out to Green Mountain. Either trip is a workout though.
A slightly easier path lies further down the road on the north rim, along Deadhorse Trail. While it is an 8 km hike from Kneeling Camel Overlook, it is a relatively easy walk along an old service road. An unnamed loop wanders out to the edge of canyon about half way along; otherwise, the trail leads out to Deadhorse gulch, and nearly opposite East Portal.
It is possible to hike the inner canyon too, but there are no maintained or marked trails in this region of the park. Only the experienced and those in excellent physical condition should attempt the descent. Encounters with wild life, extreme poison ivy, and potential for disorientation are higher than normal in any other canyon. Most trips down into the canyon will consume half or all of a day. While it will seem relatively easy going down, the geology ensures that the return trip will take twice as much time.
Geology is what makes this park unique. Along with other erosion effects, the Gunnison River has etched a permanent mark on the Colorado landscape, two billion years in the making. Indeed, it may very well be there in another two billion years, and deeper still.
The Black Canyon of the Gunnison marks a relatively indistinguishable boundary between two physiographic provinces, the southern Rocky Mountains to the east and the Colorado Plateau to the west. While both regions are generally similar, the intense folding and deformations present at this location portray different geologic processes.
At the foot of the mass of laccolith peaks and volcanic mesas that make up the West Elk Mountains, the Gunnison River cuts through a massive uplift in the landscape that occurred about 65 million years ago.
Precambrian basement rock bulged upwards, increasing the elevation from near sea level to several thousand feet above. Erosion effects of wind and rain, running water, and freezing temperatures were probably negligible until this time, and then all such processes accelerated.
Most streams flowed away from the area and began wearing down the Sawatch Range immediately to the east, though some continued their effort on the newly formed Gunnison Uplift. The Sawatch Range diminished significantly over time, and any soft sediments covering the uplift, scoured away. Only a broad, flat plain remained, where various streams meandered, and all was relatively peaceful again.
Volcanic events returned to the region after a time, depositing mountainous piles of debris, creating the West Elk Mountains and the San Juan Mountains to the south. Most drainage diverted around the south side of the West Elk Mountains and directly across the buried Gunnison Uplift.
As the region stabilized, the Gunnison River, now the only significant stream remaining became trapped and unable to alter its own course. It carried away all of the softer sediment covering the uplift, and with the help of other erosional factors, started cutting into the old Precambrian rock, permanently entrenching itself and sealing a fate of gouging out the incredible topographic relief of the Black Canyon.
Recent changes to the surrounding landscape have altered the geologic and environmental systems within the canyon. The Park, along with the associated Recreation Area to the east and the National Conservation Area to the west, attracts millions of visitors every year. For a system as dynamic as exists in this space, one capable of identifiable change within the span of a human life, some of the more pressing concerns relate to protecting geologic resources.
Ongoing paleontology discoveries within the area, exclusive to the Morrison formation that exists through much of the Colorado Plateau, are crucial to better understanding the life of the canyon and life within the canyon. These resources identify how the feature has reacted and responded to changes in the environment and are necessary to adapting and allocating future use of other biological and geological resources.
Mining is one of those primary interests, and has been since the mid-1800s. The Precambrian metamorphic and Precambrian rock hosts gold, silver, titanium, copper, vanadium (a steel additive that increases tensile strength), among numerous other highly prized metallic ores. As well, uranium deposits known to exist throughout the Morrison Formation are of keen interest. As demonstrated through past experience and scientific analysis, any sort of mining activity can and usually does lead to water contamination, which would affect the delicate ecosystem within the park.
Water is probably the biggest concern of all. This part of Colorado sees about 20 cm to 25 cm of rain annually, typical of a semi-arid climate in which water is always one of the most important resources. The Gunnison watershed, confined to the canyon and the immediate area, is critical to continuing agricultural production for the region.
Dams and diversionary tunnels implemented during the 1960s and mid-1970s had a profound impact on the region, requiring intensive management to ensure continuing availability of this resource. Recent drought activity across the southwest part of the United States continues to test limits.
A concern not just for the human population that depends on water from the river, these concerns are greatest for the residents of the Black Canyon, where flora and fauna abound. Black bear, coyote, muskrat, cougars, beaver, elk, river otter, bobcat, mule deer, pronghorn antelope, and a wide variety of resident and migratory birds call the canyon home year round.
All of this exists among a backdrop of aspen, pine, sagebrush, and juniper typical throughout much of Colorado. Wildflowers are abundant as well, one species of wildflower is native to the park, the Black Canyon Gilia, a small shrub like plant from the Phlox family.
This park is a truly amazing place, and no one article can cover the depth of this place (no pun intended). The diversity in geology, biology, and pure scenic beauty is unmatched anywhere in the United States; indeed, perhaps, anywhere in the world.
Further Reading
