Terrain: mostly flat plains or gently rolling hills in north and west; remainder is mountainous, especially Pyrenees in south, Alps in east
Abercrombie
& Kent
Active Journeys
Adventure Canada
Adventure Center
Adventures
Abroad
American Alpine Institute
Artisans of
Leisure
Austin-Lehman Adventures
Backroads
Baobab Expeditions
Boundless
Journeys
Bredeson Outdoor Adventures
Butterfield &
Robinson
Ciclismo Classico
Civilized Adventures
Classic Journeys
Country
Walkers
Cyclomundo
Discover France/Pure
Adventures
Distant Journeys
DuVine Adventures
EarthWatch Institute
ExperiencePlus!
Bicycle Tours
EXPLORE! (Martinique)
Explorers' Corner
Freewheeling Adventures
GAP Adventures
Great Explorations
iExplore
In the Saddle
Intrepid Travel
KE
Adventure Travel
Kumuka Worldwide
Lindblad Expeditions
Mountain Madness
Mountain Travel Sobek
National
Geographic Expeditions
Naturalist
Journeys
Peregrine
Adventures
REI Adventures
ROW Adventures
Ryder-Walker Alpine
Adventures
S-Cape Travel
Selkirk Mountain
Experience
Sierra Club
Outings
Sky2Sea
International
Spyns
The Wayfarers
The
World Outdoors
Trek Travel
VBT Bicycling Vacations
Wilderness
Travel
YokmoK