* The Drifters:A Saga of the Sea (1928)
* Hvidguld (1931)
* Big Jim Turner:A Story of San Francisco (1936)
* Forever Thine:A Story of Old San Francisco (1938)
* Captain Kit:A Story of Old Hawaii (1939)
* San Francisco:A Pageant (1939)
* Silver Canyon (1941)
* San Francisco:A Backward Glance (1942)
* Kineserne i Californien (1943)
* Historien om Californiens missioner (1943)
* Tales of Early California:A Collection of Stories of the First American Frontier (1943)
* Kaptajn Sam (1945)
* Guld er hvor du finder det (1946)
* The Golden Gateway (1947)
* The Captain and the Co-eds (1949)
* The Green Fairy:A Story of Absinthe and the Artists (1950)
* The Lost City of the Maya:A Story of Yucatan (1951)
* Den flyvende opstand (1951)
* Don Juan:A Story of Old Spain (1952)
* The Spanish Mission Story:A Story of the Pacific Coast (1953)
* El Dorados hemmelighed (1954)
* The Enchanted Land:A Story of Old Mexico (1955)
* The Golden Hills:A Story of the Old West (1956)
* The Painted Desert:A Story of the Southwest (1957)
* The Grand Canyon:A Story of the Colorado River (1958)
* The Yellowstone:A Story of the First National Park (1959)
* The Great Smoky Mountains:A Story of the First National Park in the East (1960)
* The Grand Tetons:A Story of the First National Park in the Rocky Mountains (1961)
* The Olympic Rain Forest:A Story of the First National Park in the Pacific Northwest (1962)
* The Everglades:A Story of the First National Park in the Subtropics (1963)
* Hawaii National Parks:A Story of the First National Parks in the Pacific (1964)
* The Mammoth Cave:A Story of the First National Park in the Underground (1965)
* The Carlsbad Caverns:A Story of the First National Park in the Southwest (1966)
* The Sequoia-Kings Canyon:A Story of the First National Parks in the Sierra Nevada (1967)
* The Yosemite:A Story of the First National Park in Californien (1968)
* The Acadia:A Story of the First National Park in the Northeast (1969)
* Kanaløerne:En historie om de første nationalparker i Stillehavet (1970)
* The Death Valley:A Story of the First National Park in the Desert (1971)
* The Bryce Canyon:A Story of the First National Park in Utah (1972)
* The Zion:A Story of the First National Park in Utah (1973)
* The Canyonlands:A Story of the First National Park in Utah (1974)
* The Arches:A Story of the First National Park in Utah (1975)
* The Capitol Reef:A Story of the First National Park in Utah (1976)
* The Katmai:A Story of the First National Park in Alaska (1977)
* The Glacier Bay:A Story of the First National Park in Alaska (1978)
* The Gates of the Arctic:A Story of the First National Park in Alaska (1979)
* Wrangell-St. Elias:A Story of the First National Park in Alaska (1980)
* Kenai Fjords:A Story of the First National Park in Alaska (1981)
* The Denali:A Story of the First National Park in Alaska (1982)
* The Kobuk Valley:A Story of the First National Park in Alaska (1983)
* The Noatak:A Story of the First National Park in Alaska (1984)
* The Gates of the Arctic:A Story of the First National Park in Alaska (1985)
* Wrangell-St. Elias:A Story of the First National Park in Alaska (1986)
* The Kenai Fjords:A Story of the First National Park in Alaska (1987)
* The Denali:A Story of the First National Park in Alaska (1988)
* The Kobuk Valley:A Story of the First National Park in Alaska (1989)
* The Noatak:A Story of the First National Park in Alaska (1990)
* The Gates of the Arctic:A Story of the First National Park in Alaska (1991)
* Wrangell-St. Elias:A Story of the First National Park in Alaska (1992)
* The Kenai Fjords:A Story of the First National Park in Alaska (1993)
* The Denali:A Story of the First National Park in Alaska (1994)
* The Kobuk Valley:A Story of the First National Park in Alaska (1995)
* The Noatak:A Story of the First National Park in Alaska (1996)
* The Gates of the Arctic:A Story of the First National Park in Alaska (1997)
* Wrangell-St. Elias:A Story of the First National Park in Alaska (1998)
* The Kenai Fjords:A Story of the First National Park in Alaska (1999)
* The Denali:A Story of the First National Park in Alaska (2000)
* The Kobuk Valley:A Story of the First National Park in Alaska (2001)
* The Noatak:A Story of the First National Park in Alaska (2002)
* The Gates of the Arctic:A Story of the First National Park in Alaska (2003)
* Wrangell-St. Elias:A Story of the First National Park in Alaska (2004)
* The Kenai Fjords:A Story of the First National Park in Alaska (2005)
* The Denali:A Story of the First National Park in Alaska (2006)
* The Kobuk Valley:A Story of the First National Park in Alaska (2007)
* The Noatak:A Story of the First National Park in Alaska (2008)
* The Gates of the Arctic:A Story of the First National Park in Alaska (2009)
* Wrangell-St. Elias:A Story of the First National Park in Alaska (2010)
* The Kenai Fjords:A Story of the First National Park in Alaska (2011)
* The Denali:A Story of the First National Park in Alaska (2012)
* The Kobuk Valley:A Story of the First National Park in Alaska (2013)
* The Noatak:A Story of the First National Park in Alaska (2014)
* The Gates of the Arctic:A Story of the First National Park in Alaska (2015)
* Wrangell-St. Elias:A Story of the First National Park in Alaska (2016)
* The Kenai Fjords:A Story of the First National Park in Alaska (2017)
* The Denali:A Story of the First National Park in Alaska (2018)
* The Kobuk Valley:A Story of the First National Park in Alaska (2019)
* The Noatak:A Story of the First National Park in Alaska (2020)
* The Gates of the Arctic:A Story of the First National Park in Alaska (2021)
* Wrangell-St. Elias:A Story of the First National Park in Alaska (2022)
noveller
* "Manden der så fremtiden"
* "Kvinden i den hvide kjole"
* "The Phantom Ship"
* "Astekernes forbandelse"
* "Inkaernes skat"
* "The Lost City of Maya"
* "De syv byer i Cibola"
* "Ungdommens Kilde"
* "Livets eliksir"
* "Skæbnens sten"
* "Den hellige gral"
* "Pagtens Ark"
* "Israels ti fortabte stammer"
* "Atlantis:Det forsvundne kontinent"
* "Lemuria:The Lost Continent"
Artikler
* "San Francisco:Et festspil"
* "Kineserne i Californien"
* "Historien om Californiens missioner"
* "Tales of Early California:A Collection of Stories of the First American Frontier"
* "Kaptajn Sam"
* "Guld er hvor du finder det"
* "Den gyldne port"
* "Kaptajnen og co-eds"
* "Den grønne fe:A