Shinumo Amphitheater has many attractions. Numerous faults occur along the river in this area, and as is the case with faults in the Canyon generally, they expose rocks of the Grand Canyon Supergroup. In the prior post, we saw, at Mile 106, both the Bass Limestone at riverside and the Shinumo Quartzite ahead. The South Bass Trail comes to the river at the head of Bass Rapid (Mile 107), and the North Bass Trail starts a little downstream, at Lower Bass Camp, on river right at Mile 108.3. Also found at the head of Bass Rapid, on river left, is the abandoned metal boat, the Ross Wheeler. The ruins of a cable crossing built by William Bass is seen further downstream, on river left at Mile 108.

Bass Rapid, Mile 107.7. The trail to Shinumo Creek can be seen cutting across a hillside, in photo center.

Seen at the mouth of Hotauta Canyon, river right at Mile 107.7, are tilted layers of the Shinumo Quartzite, overlain by another Supergroup rock, the Dox Sandstone. The light-colored ridge seen above descends from a monument known as the Dox Castle. This is the so-called type locality, meaning the Dox Sandstone was first studied, described and named here.
The roomy Lower Bass Camp, on river right at Mile 108.3, is a much-coveted lay-over camp. It gives access to the North Bass Trail, which follows Shinumo Creek and the tributary White Creek upstream. One can also turn downstream, and hike a short ways to where a downclimb through boulders leads to the waterfall. The shoreline upstream from camp has some of the most interesting fluted and polished rocks in the Canyon.

Upstream view of Bass Camp and Dox Castle (upper left), from the hilltop to the downstream side of camp.
The mouth of Shinumo Creek is just downstream of Bass Camp, but a cliff intervenes between the two. The creek and waterfall are usually visited after pushing off from Bass Camp.
Note: This and prior posts on the subject are excerpted from my iBook: “The Grand, the Colorado River in the Grand Canyon, a Photo Journey and Visual Guide, 2nd. edition”. The book costs $5.99 and is available from the iTunes Store, using this link: https://itunes.apple.com/us/book/the-grand/id672492447?ls=1