PIEDMONT -- A malfunctioning insulin pump caused Bob Coomber, aka "4WheelBob," to abort his climb over Kearsarge Pass to become the first person in a wheelchair to cross the Sierra Nevada.

The 58-year-old Coomber, who grew up in Piedmont and lives in Livermore, has been diabetic since youth. Complications from diabetes have caused bone degeneration and brittleness in his legs since 1990 when he became wheelchair-bound.

Undaunted, the outdoorsy Coomber is a goodwill ambassador for the disabled, giving motivational talks to clubs and schools to get out and experience nature. He has wheelchair-hiked more than 100 Bay Area parks, and scaled 14,000-foot White Mountain in Mono County.

He is a member of East Bay Regional Parks' Park Advisory Committee, an all-volunteer citizens' advisory group, and a board member for Livermore Area Recreation and Park District. Coomber was disappointed that his insulin pump failed not far into the rugged trail on Sept. 24.

"It annoyed me to no end. No question it was a horribly difficult trail, with boulder after boulder," Coomber said.

The extreme exertion Coomber experienced having to manually swing his chair around each boulder coupled with the lack of insulin he needed caused his blood sugar to spike to dangerous levels -- between 400 and 500.

"I kept pushing, but I was starting to get really sore and feeling weird, " Coomber said.

Ketoacidosis set in about two miles up the trail, causing extreme muscular soreness and nausea. Coomber knew he had to turn back with his two companions, a hiker friend familiar with the mountain and Tal Skloot, who was filming the trek for a documentary.

"I was in life-threatening diabetic coma territory," Coomber said.

The group arrived Sept. 23 in Onion Valley at the trailhead to acclimate to the 12,000-foot elevation Kearsarge Pass climb. They set out Sept. 24, but after a few hours on the trail they returned and took Coomber to the hospital in Bishop to be checked out. He returned home Sept. 25.

He'll try again next year and be better prepared with a lighter pack and more insulin kits, he said.

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