1956
Bibliografía (21 obras)
Opening doors
2014
The carry home
Wo der Adler wohnt
2005
The Great Divide
2004
Hawks rest
2003
Guide to America's outdoors
2000
National Geographic Guide to America's Outdoors
Shouting at the sky
1999
Through the woods
1998
The sylvan path
1997
The Yellowstone wolves
1996
Spirits of the wild
Northwest walks
1995
New England walks
Rocky Mountain walks
1993
Walking down the wild
Walks of the Pacific Northwest
1991
Walks of the Rockies
1988
Walks of California
1987
Freewheeling
1984
Folklore of medicinal plants and herbs
1970
