Region
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La Brea Pits (Calif.)
1
Lake Clark National Park and Preserve
1
Lake Clark National Park and Preserve (Alaska)
1
Lethbridge (Alta.)
1
Luján River (Buenos Aires)
1
McMurdo Sound Region
1
Medicine Hat (Alta.)
1
Meridian
1
Milk River Valley (Mont. and Alta.)
1
Mississippi
2
Mongolia
1
Montana
2
Nebraska
1
Nevada
1
New Zealand
1
North America
3
North Atlantic Ocean
1
Ohio
3
Oregon
1
Panama
1
Pennsylvania
2
Pittsburgh
1
Prince George (B.C.)
1
Puerto Rico
1
San Pedro River Valley (Mexico and Ariz.)
1
South America
1
South Dakota
1
Spain
1
Terre
1
Texas
1
Tumbler Ridge (B.C.)
1
United States
28
United States, West
1
Urumaco
1
Venezuela
1
Victoria (B.C.)
1
Warner (Alta.)
1
West (U.S.)
7
Wilcox Group
1
Willow Creek (Alta.)
1
Wyoming
2