The naturally formed Redwall Cavern, Colorado River, Grand Canyon National Park, UNESCO World Heritage Site, Arizona, United States of America, North America

The Redwall Cavern, a giant cave in the walls of the Grand Canyon, seen while rafting down the Colorado River, Grand Canyon, Arizona, United States of America, North America

The Redwall Cavern, a giant cave in the walls of the Grand Canyon, seen while rafting down the Colorado River, Grand Canyon, Arizona, United States of America, North America

Tourists in the Redwall Cavern, Grand Canyon, Arizona, USA, America

Hikers setup camp on a beach along the Colorado River near the plumeting 180-foot Deer Creek Falls in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers on the sandstone Esplanade of the Thunder River Trail below the North Rim of the Grand Canyon outside Fredonia, Arizona November 2011. The 21.4-mile loop descends 2000-feet in 2.5-miles through Coconino Sandstone from the Bill Hall trailhead to connect the Thunder River and Deer Creeks trails. Hikers descend into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley, Deer Creek, Tapeats Creek via Thunder River and even the Colorado River.

Male hiker filters water on a cliff-pinched patio near Deer Creek Falls in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers setup camp on a beach along the Colorado River near the plumeting 180-foot Deer Creek Falls in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers swim in the pool below 180-foot Deer Creek Falls in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers descend into Surprise Valley to access the lower canyon through a break in the 400-foot-tall Redwall on the Thunder River Trail in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon to access Thunder River, Tapeats Creek and Deer Creek.

Hikers walk along Deer Creek Narrows in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers walk along Deer Creek Narrows in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers follow a route along the Colorado River that connect Tapeats Creek and Thunder River to Deer Creek in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers walk along Deer Creek Narrows in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers cook dinner along Deer Creek Narrows in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers overlook the Colorado River as they exit the Deer Creek Narrows in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers climb out of Surprise Valley to the North Rim of the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers on the sandstone Esplanade of the Thunder River Trail below the North Rim of the Grand Canyon outside Fredonia, Arizona November 2011. The 21.4-mile loop descends 2000-feet in 2.5-miles through Coconino Sandstone from the Bill Hall trailhead to connect the Thunder River and Deer Creeks trails. Hikers descend into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley, Deer Creek, Tapeats Creek via Thunder River and even the Colorado River.

Hikers on the sandstone Esplanade of the Thunder River Trail below the North Rim of the Grand Canyon outside Fredonia, Arizona November 2011. The 21.4-mile loop descends 2000-feet in 2.5-miles through Coconino Sandstone from the Bill Hall trailhead to connect the Thunder River and Deer Creeks trails. Hikers descend into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley, Deer Creek, Tapeats Creek via Thunder River and even the Colorado River.

Female hiker cooks dinner on a cliff-pinched patio above camp and the Colorado River near Deer Creek Falls in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers setup camp on a beach along the Colorado River near the plumeting 180-foot Deer Creek Falls in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers follow a route along the Colorado River that connect Tapeats Creek and Thunder River to Deer Creek in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers walk along Deer Creek Narrows in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Male hiker filters water on a cliff-pinched patio near Deer Creek Falls in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers walk along Deer Creek Narrows in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers past small waterfalls along Deer Creek Narrows in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Male hiker filters water on a cliff-pinched patio near Deer Creek Falls in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Hikers cook dinner on a cliff-pinched patio above camp and the Colorado River near Deer Creek Falls in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.