United States
American Alpine Club
American Discovery Trail Society
American Hiking Society
American Long Distance Hiking Association West
Appalachian Long Distance Hiking Association
Appalachian Mountain Club
Appalachian Mountain Club - DC Chapter
Barefoot Hikers
Colorado Mountain Club
Fortune Bay Expeditionary and Recovery Team
Grand Canyon Hikers and Backpackers Association
Leave No Trace
Mountaineers
National Parks and Conservation Association
National Parks Service
National Parks Trust
Native Forest Council
Pacific Northwest Trail Association
Outdoors Club


Canada
Alpine Club of Canada
The Bruce Trail Organization
East Coast Trail Association
Federation of Mountain Clubs of British Columbia
Ganaraska Trail Association
Grant MacEwan Mountain Club
Hike Ontario
International Appalachian Trail
North Shore Hikers
Sierra Club Atlantic Canada Chapter
Trailpaq
Voyageur Trail Association


UK/Europe
Backpackers Club
Landcaster University Hiking Club
Nuneaton Rambling Club
Ramblers Association
River Parrett Trail
Suomen Latu Hiking Organization -- Finland


Australia/New Zealand
Archipelagao
Budget Backpacker Hostels -- New Zealand
Confederation of Bushwalking Clubs NSW Inc
Federated Mountain Clubs of New Zealand
North Shore Tramping Club
Mountain Dragon Bushwalkers
Wellington Tramping and Mountaineering Club


Africa
Johannesburg Hiking Club


If you know of a good link we should add — let us know. Thanks.