Bromide Hill
Blome and others, 2013
Graham, 2015
NPS GRI Team, 2015b
Hohmann and others, 2007
Cades Cove
NPS web page, 2023d
NPS GRI Team, 2019a
NPS GRI Team, 2019b
Repetski, 1997
Southworth and others, 2000
Thornberry-Ehrlich, 2008a
USGS web page, undated[h]
Cadillac Mountain
Braun, 2019
Graham, 2010a
NPS web page, 2023a
NPS GRI Team, 2010a
USGS web page, undated[b]
Camel Rock
Denny and others, 2008
Frankie, 2009
Frankie and Jacobson, 2001
USFS website, undated[b]
Catoctin Mountain
Brezinkski, 2021
NPS website, 2016
NPS GRI Team, 2009a
Thornberry-Ehrlich, 2009a
Cowards Hollow
Harrison and McDowell, 2003
Missouri Department of Conservation website, undated
USFS web page, 2008
Cumberland Gap
Crawford & Hunsberger, 2011
NPS GRI Team, 2010a
Thornberry-Ehrlich, 2011
Cumberland Island Salt Marsh
Cooke, 1943
Henderson and others, 2022e
Lawton and others, 1975
NPS website, 2018a
NPS website, 2018c
Deer Leap Rock
Ackerly and Larsen, 1987
Brace, 1953
Ratcliffe and others, 2011
USFS web page, undated[a]
USFS website, undated[d]
Devil's Den
Cuffy and others, 2008
NPS GRI Team, 2009c
Reese, 2016
Thornberry-Ehrlich, 2009c
Devils Island
Henderson and others, 2021c
Mudrey and others, 1982
NPS GRI Team, 2015a
Thornberry-Ehrlich, 2015
Devils Postpile
Graham, 2010b
Huber and Rinehart, 1965
NPS GRI Team, 2009b
Dunes of White Sands National Park
KellerLynn, 2012
Kelley and others, 2014
NPS GRI Team, 2012
Pigati and others, 2023
Exit Glacier
Kurtz and Baker, 2016
Lanik and others, 2018
NPS GRI Team, 2017a
Wilson and Hults, 2012
Flint-rich limestone of Tallgrass Prairie National Reserve
Barthelmes, 2022
Curdts and Chappell, 2022
Sawin, 2008
NPS website, 2022a
Great Basin Curvilinear Style Petroglyph
McKee, 1976
Guadalupe Peak
Henderson and others, 2021b
KellerLynn, 2008
King, 1948
NPS web page, 2022c
NPS website, 2023b
NPS website, 2023c
NPS GRI Team, 2007a
USGS web page, undated[i]
Hammock Sink
USFS website, undated[b]
Williams and Kuniansky, 2016
Wisenbaker, 2000
Hanging Rock
Graham, 2011
Henderson and others, 2022a
NPS website, 2015a
NPS website, 2015d
NPS website, 2022g
Witzke and Anderson2006
WitzkeOthers2010
Kilauea caldera
Casadevall and Dzurisin, 1987
NPS GRI Team, 2009d
Peterson, 1967
Thornberry-Ehrlich, 2009d
USGS web page, undated[j]
La Coca Falls
Quiñones and others, 2018
Seiders, 1971
USFS website, undated[c]
Landscape Arch
Doelling and Kuehne, 2014
Graham, 2004
NPS web page, 2021
NPS GRI Team, 2018a
USGS web page, undated[c]
Little River Canyon
Curdts and others, 2022
NPS website, 2021a
Thornberry-Ehrlich, 2022
Looking Glass Rock
Carter and others, 2016
Marsh-Felch Quarry
Carpenter and Lindsey, 2019
Grenard and others, 2019
Wobus and others, 1985
Mather Gorge
Southworth and Denenny, 2006
Thornberry-Ehrlich, 2009b
NPS website, 2015b
NPS website, 2015c
NPS web page, 2023c
NPS GRI Team, undated
Metolius Balancing Rocks
Pitcher and others, 2021
Monument Rock
Huber, 1973a
Huber, 1973b
Huber, 1975
NPS GRI Team, 2008b
Thornberry-Ehrlich, 2008b
Mount St. Helens
Lipman and Mullineaux, 1981
USGS web page, undated[l]
New River Gorge sandstone cliffs
Henderson and others, 2021a
Hennen, 1919
NPS GRI Team, 2017b
Thornberry-Ehrlich, 2017
Old Faithful Geyser
Christiansen, 2001
Hilario, 2022
Koch and others, 2011
Morgan and others, 2017
USGS web page, 2020[b]
Passaic Falls
Volkert, 2006
Pompeys Pillar
BLM website, undated
Lopez, 2000
NPS web page, 2023b
Price Neck Formation
Dietsch and others, 2019
Hermes and others, 1994
Rast and Skehan, 1981
USFWS website, undated
Pulpit Rock
NPS website, undated[b]
NPS GRI Team, 2009e
NPS GRI Team, undated
Southworth and Denenny, 2006
Thornberry-Ehrlich, 2009e
Race Point Beach
Stone and DiGiacomo-Cohen, 2009
Stone and others, 2018
NPS website, 2017
NPS website, 2018b
USGS web page, undated[d]
Ram Head
Hall and KellerLynn, 2010
NPS GRI Team, 2019c
Rankin, 2002
Ritidian Point
Siegrist and Reagan, 2007
Scotts Bluff
Graham, 2009
Henderson and others, 2022c
NPS website, 2023a
NPS website, 2023d
NPS GRI Team, 2018b
Swinehart and Diffendal, 1997
Sheep Rock
Vallier, 1974
Ship Island
Morton and Rogers, 2010
NPS GRI Team, 2019d
Schupp, 2019
Sod Tables of the Badlands
Graham, 2008
NPS web page, 2020a
NPS web page, 2020b
NPS GRI Team, 2008a
Tar Point
Graham, 2007
Hemstad and others, 2002
Jirsa, 2011
NPS website, 2023e
NPS GRI Team, 2007b
The Giant Flowstone of Blanchard Springs Caverns
Braden and others, 2002
Chandler, 2014
USFS website, undated[b]
USFS web page, undated[e]
The Great Unconformity at Grand Canyon
Billingsley and Hampton, 2000
Billingsley and others, 2012
Graham, 2020
Hilario, 2022
Huntoon and others, 1996
Maxson, 1961
NPS web page, 2024
NPS GRI Team, 2020c
USGS web page, undated[g]
The Ritchie Ledges
Larsen and Slucher, 1996
NPS web page, 2022e
NPS website, 2023g
NPS GRI Team, 2020a
Swinford and others, 2011
Thornberry-Ehrlich, 2020a
USGS web page, undated[f]
The Truants' Meadow outcrop
London, 1984a
London, 1984b
Henderson and others, 2022b
NPS website 2022j
NPS website, 2023h
NPS GRI Team, 2011b
Thornberry-Ehrlich, 2012
Tuckerman Ravine
Allen and others, 2002
Fowler, 2010
Goldthwait, 1940
Two-Top Mesa and Big Top Mesa
Gonzalez, 2004
NPS website, undated[c]
Vai'ava Strait of Pola Island
Henderson and others, 2022d
NPS GRI Team, 2018c
Stearns, 1944
Thornberry-Ehrlich, 2008c
West Beach Dunes
NPS website, 2022f
NPS website 2022i
NPS web page, 2023c
NPS GRI Team, 2020b
Schneider and Kelly, 1970
Thornberry-Ehrlich, 2020b
USGS web page, undated[k]
Weston Lake
Graham, 2014
NPS GRI Team, 2014
Willoughby and others, 2010
USGS web page, undated[e]
Wilderness Breach
Fletcher and Kintz, 1979
Fuller, 1914
NPS website 2022k
O'Meara, 2023
Thrasybule, 2016
Wissahickon Formation of the Delaware Piedmont
Plank and others, 2000
Schenck, 2021
Wolf Rock Cave
Snead and McCulloh, 1984
USFS web page, undated[f]