Off-Road Trekking for Wheelchair Users

From Quest magazine:

Full-time wheelchair users with a hankering to enjoy the great rugged outdoors may find that their standard chairs can't always take them where they want to go. That's where these specially designed conveyances can step up to the job.
Even extreme locations like the climbers' camp at the base of Mt. Everest have been reached and conquered by severely disabled people riding in these unusual-looking contraptions, which typically are pushed and/or pulled by friends and acquaintances affectionately known as "Sherpas."
Here's a look at some of the options available for accessible hiking, skiing and general outdoor fun.

http://quest.mda.org/article/road-trekking-wheelchair-users