While rocks are nothing new to the Grand Canyon, Ten Mile Rock is fairly interesting due to its shape and balanced position in the river. The name is obvious, but as you pass by you have hit the ten mile point since launching at Lee’s Ferry.
A long-standing tradition is to tell newcomers that the NPS flew the rock into the canyon to create a visual mileage marker for boaters. Feel free to spin the gag on them and ‘believe’ them with over the top enthusiasm. Double points if you then ask about other visual clues at each mileage decade that the NPS flew in. Have fun 🙂
Trent Nelson has some interesting photos of a high water trip in 1996 showing the slab. Here’s a link to the photos and blogpost.
Photo by the NPS. Public domain.