At Black Canyon, the Gunnison River carves through rock that is 1.7 billion years old, some of the oldest rock on the planet. Called basement rock, it forms the foundation of Earth’s crust and is only exposed occasionally, such as at the lower levels of the Grand Canyon. The block of basement rock that Black Canyon is carved through is called the Gunnison Uplift. Once exposed, the upper portions of the uplift had eroded away before the Rocky Mountains formed. Sixty million years ago, the same massive, continental rising that birthed the Rockies also lifted the Gunnison Uplift, priming it for another round of erosion.
Thirty million years ago, the West Elk Mountains to the north of the Gunnison Uplift and the San Juan Mountains to the south of it were volcanic, spewing ash that buried the uplift once again. The rise of the West Elks forced the ancestral Gunnison River to flow to the south of these new mountains. The river cut easily through the volcanic tuff and sedimentary rock between the West Elks and the San Juans.
But farther down, the river hit the much harder basement rock of the Gunnison Uplift. By now it was too late, the river’s course was set and it continued to carve, slowly, through this much harder rock where it was now exposed on the surface for sixty-five miles.
On the afternoon of August 30, after our misadventures in Curecanti National Recreation Area and abandoned attempt to reach the north rim, we decided to tour the south rim’s viewpoints from the visitor center west to the end of the road.
Our first stop was Pulpit Rock Overlook with its fine views east into the canyon.
From Pulpit Rock, so called because it juts out from the rim like the pulpit in a church, we had fine views 1,800 feet down to the river.
We were late for the afternoon Ranger talk at the overlook, but we listened a bit from afar as we gazed at the view.
The narrowness of the canyon bottom, even at the relatively wide portion that we could see from Pulpit Rock, was incredible.
Beyond the immediate foreground of the canyon, the visibility wasn’t particularly great from the wildfire smoke wafting across the Great Basin and Colorado Plateau from California.
Still we could glimpse the closest peaks of the West Elks to the north.
Continuing on, we stopped next at Cross Fissures Views. Here and at the next lookout, the canyon was much narrower as the river approached The Narrows.
Here it felt like you could almost reach out and touch the north wall.
On our side of the canyon, there was a series of very steep side canyons, formed by ice and water eroding the canyon walls along the natural cracks and faults in the hard, mind-bendingly ancient rock.
Despite its name, the canyon is colorful, with striking mineral striping.
The density and hardness of the rock encourage the formation of fins and pinnacles rising dizzyingly from the canyon.
Sean, who has relatively little fear of heights, declared that this place was something else. It’s so steep, so abrupt that it’s hard not to feel a little dizzy at the cliff edges.
We left Cross Fissures and continued a very short way to the next viewpoint, Rock Point.
Beneath Rock Point, we had a good view of The Narrows, where the canyon is only forty feet wide while its walls are 1,700 feet high.
The Gunnison River was able to carve such a deep canyon out of such hard, unyielding rock because its run through Black Canyon is exceptionally steep. Along the short stretch of the river that The Narrows is the heart of, the river drops 480 feet, practically a slow waterfall. Before it was impounded by the three upstream dams, the force and violence of the river during spring thaw in the mountains would have been immense.
After gawking at The Narrows from Rock Point and Devil’s View, we continued on to Chasm View
Here the north wall was a sheer cliff (although not the highest cliff in the canyon).
Atop this cliff was the area of the north rim’s primitive campground. We spotted fellow visitors taking in the view from the other side.
The overlooks between Chasm View and the end of the road mostly faced west as the canyon made a southerly turn. We decided to skip these since we’d be staring into the late afternoon sun and return to them in the morning.
Instead, we’d cap our afternoon of exploring with the hike to Warner Point.