We are deep within the metamorphic rocks of Granite Gorge, more than a mile below the rim of Grand Canyon. At river mile 88, in the area of Phantom Ranch, we cross beneath two narrow bridges. 
In 1928, construction of the Kaibab (Black) Bridge changed the dynamics of tourism along the Colorado River. Its purpose was to connect the North Kaibab trail and the South Kaibab trail, making travel across the river safer for both humans and mule traffic.
A short distance downstream is the Bright Angel (Silver) Bridge, built in the late 1960s. This bridge not only brings hikers from the south rim to Phantom Ranch but also is the support structure for an extensive water pipeline that brings water from Roaring Springs on the north rim down Bright Angel Canyon, through Phantom Ranch, across the Colorado River, and up to the south rim.
These two bridges are the only permanent access across the river for hundreds of miles either upstream or down.
It is a cold, wet day as we travel downstream to our second rendezvous with the tilted beds of the Grand Canyon Supergroup. Lunchtime is a soggy maelstrom of shivering humanity. With the sun still obscured behind a thick veil of clouds, there is just no chance to get warm. For lunch, all I want is a large cup of hot tea. I have no desire to choke down a cold sandwich. Back on the boat, I am too cold to even take pictures.
The night’s camp is downstream of Bass Rapid on a narrow, rocky shelf of sand. Wet clothes are draped to dry over every available surface. The sky clears and I am warm once again. I think I’m warm enough to have a beer.
