I once knew,worked with and hiked with a 80+ year old man in the Grand Canyon who in his 80th year hiked 104 rim to rims across the canyon. I hiked with him on his first R2R in early 1999. In this narrative he talks about the Grand Canyon. Sadly he died in early 2009." I miss you my good Friend and hiking companion!" His name was Maverick a name he gave himself.
His average speed was 1 mile an hour. On our first R2R it took him 19 hours to cross the 23 miles from the North to South Rims. I took 7 hours as he told me to hike at my own pace and not wait up for him.
This video shows him talking about the Grand Canyon http://arrowheadfilms.com/docume…/voices-of-the-grand-canyon