Bob Coomber's Sierra Nevada wheelchair expedition
Credit: Getty Images

Bob Coomber has been in a wheelchair since diabetes left him with severe osteoporosis 20 years ago. The former police officer is now a devoted hiker and became the first person in a wheelchair to climb California's 14,250-foot White Mountain Peak. He attempted an east-to-west crossing of the Sierra Nevada along the Kearsage Pass trail last fall but was thwarted by a malfunctioning insulin pump. Rested and ready, he's giving the trail a second shot. He aims to complete the 22-mile, weeklong journey to Kings Canyon National Park this July (2014).