Wilderness areas - Environmental aspects - United States.

Wildland recreation : = ecology and management / by: (Language materials, printed)

Walking softly in the wilderness : = the Sierra Club guide to backpacking / by: (Language materials, printed)

Meeting the tree of life : = a teacher's path / by: (Language materials, printed)

NOLS soft paths : = how to enjoy the wilderness without harming it / by: (Language materials, printed)

Outdoor recreation- Environmental aspects- United States.

Tallmadge, John- Journeys- United States.

Wilderness areas- Recreational use- United States

Environmentalists- United States

Backpacking- United States.

Backpacking.

Wilderness areas- Environmental aspects- United States.

Environmentalism.