ALABAMA

• Beaverdam Creek Swamp
• Cathedral Caverns
• The Dismals Canyon
• Mobile-Tensaw River Bottomlands
• Newsome Sinks Karst Area
• Red Mountain Expressway Cut
• Shelta Cave

ALASKA

• Aniakchak Crater
• Arrigetch Peaks
• Bogoslof Island
• Clarence Rhode National Wildlife Range
• Iliamna Volcano
• Lake George
• Malaspina Glacier
• McNeil River State Game Sanctuary
• Mount Veniaminof
• Redoubt Volcano
• Shishaldin Volcano
• Simeonof Island, Simeonof National Wildlife Refuge
• Unga Island
• Walker Lake
• Walrus Islands
• Worthington Glacier

ARIZONA

• Barringer Meteor Crater
• Canelo Hills Cienega
• Comb Ridge
• Grapevine Mesa Joshua Trees
• Onyx Cave
• Kaibab Squirrel Area
• Patagonia-Sonoita Creek Sanctuary
• Ramsey Canyon
• Willcox Playa

ARKANSAS

• Blue Lake Natural Area
• Lake Winona Research Natural Area
• Mammoth Spring
• Roaring Branch Research Natural Area
• White River Sugarberry Natural Area

CALIFORNIA

• Amboy Crater
• American River Bluffs and Phoenix Park Vernal Pools
• Ano Nuevo Point and Island
• Anza-Borrego Desert State Park
• Audubon Canyon Ranch
• Black Chasm Cave
• Burney Ralls
• Cinder Cone Natural
• Cosumnes River Riparian Woodlands
• Deep Springs Marsh
• Dixon Vernal Pools
• Elder Creek
• Emerald Bay
• Eureka Dunes
• Fish Slough
• Imperial Sand Hills
• Irvine Ranch
• Miramar Mounds
• Mitchell Caverns and Winding Stair Cave
• Mount Diablo State Park
• Mount Shasta
• Nipomo Dunes-Point Sal Coastal Area
• Pixley Vernal Pools
• Point Lobos State Reserve
• Pygmy Forest
• Rainbow Basin
• Rancho La Brea
• San Andres Fault
• San Felipe Creek Area
• Sand Ridge Wildflower Preserve
• Sharktooth Hill
• Tijuana River Estuary
• Torrey Pines State Reserve
• Trona Pinnacles
• Turtle Mountains Natural Area

COLORADO

• Garden of the Gods
• Garden Park Fossil Area
• Indian Springs Trace Fossil Site
• Lost Creek Scenic Area
• Morrison Fossil Area
• Raton Mesa
• Roxborough State Park
• Russell Lakes
• Sand Creek
• Slumgullion Earthflow
• Spanish Peaks
• Summit Lake

CONNECTICUT

• Bartholomew's Cobble
• Beckley Bog
• Bingham Pond Bog
• Cathedral Pines
• Chester Cedar Swamp
• Dinosaur Trackway
• McLean Game Refuge Natural Areas
• Pachaug-Great Meadow Swamp

FLORDIA

• Archbold Biological Station
• Big Cypress Bend
• Corkscrew Swamp Sanctuary
• Devils Millhopper
• Emerald March
• Florida Caverns Natural Area
• Ichetucknee Springs
• Lignumvitae Key
• Manatee Springs
• Osceola Research Natural Area
• Paynes Prairie
• Rainbow Springs
• Reed Wilderness Seashore Sanctuary
• San Felasco Hammock
• Silver Springs
• Torreya State Park
• Wacasassa Bay State Preserve
• Wakulla Springs

GEORGIA

• Big Hammock Natural Area
• Camp E. F. Boyd Natural Area
• Cason J. Callaway Memorial Forest
• Ebenezer Creek Swamp
• Heggie's Rock
• Lewis Island Tract
• Marshall Forest
• Okefenokee Swamp
• Panola Mountain
• Wassaw Island

HAWAII

• Diamond Head
• Iao Valley
• Kanaha Pond
• Koolau Range Pali
• North Shore Cliffs
• Makalawena Marsh
• Mauna Kea

IDAHO

• Big Southern Butte
• Big Springs
• Cassia Silent City of Rocks
• Crater Rings
• Great Rift System
• Hagerman Fauna Sites
• Hell's Half Acre Lava Field
• Hobo Cedar Grove Botanical Area
• Menan Buttes
• Niagara Springs
• Sheep Rock

ILLINOIS

• Allerton Natural Area
• Bell Smith Springs
• Busse Forest Nature Preserve
• Forest of the Wabash
• Fults Hill Prairie Nature Preserve
• Funks Grove
• Giant City Geological Area
• Heron Pond-Little Black Slough Natural Area
• Horseshow Lake Nature Preserve
• Illinois Beach Nature Preserve
• LaRue-Pine Hills Ecological Area
• Little Grand Canyon Area
• Lower Cache River Swamp
• Lusk Creek Canyon
• Markham Prairie
• Mississippi Palisades
• Volo Bog Nature Preserve
• Wauconda Bog Nature Preserve

INDIANA

• Big Walnut Creek
• Cabin Creek Raised Bog
• Calvert and Porter Woods Nature Preserve
• Cowles Bog
• Davis-Purdue Agricultural Center Forest
• Donaldson Cave System and Woods
• Dunes Nature Preserve
• Fern Cliff
• Hanging Rock and Wabash Reef
• Harrison Spring
• Hemmer Woods
• Hoot Woods
• Hoosier Prairie
• Kramer Woods
• Marengo Cave
• Meltzer Woods
• Officer's Woods
• Ohio Coral Reefs (Falls of the Ohio)
• Pine Hills Natural Area
• Pinhook Bog
• Pioneer Mother's Memorial Forest
• Portland Arch Nature Preserve
• Rise at Orangeville
• Rocky Hollow-Falls Canyon Nature Preserve
• Shrader-Weaver Woods
• Tamarack Bog Nature Preserve
• Tolliver Swallowhole
• Wesley Chapel Gulf
• Wesselman Park Woods
• Wyandotte Cave

IOWA

• Anderson Goose Lake
• Cayler Prairie
• Cold Water Cave
• Dewey's Pasture and Smith's Slough
• Hayden Prairie
• Loess Hills
• White Pine Hollow Preserve

KANSAS

• Baker University Wetlands
• Baldwin Woods
• Big Basin Preserve
• Monument Rocks Natural Area
• Rock City

KENTUCKY

• Big Bone Lick
• Creelsboro Natural Bridge
• Henderson Sloughs
• Lilley Cornett Woods
• Ohio Coral Reef (Falls of the Ohio)
• Red River Gorge
• Rock Creek Research Natural Area

MAINE

• Appleton Bog Atlantic White Cedar Stand
• Bigelow Mountain
• Carrying Place Cove
• Colby-Marston Preserve
• Crystal Bog
• Gulf Hagas
• The Hermitage
• Monhegan Island
• Mount Katahdin
• New Gloucester Black Gum Stand
• Number 5 Bog and Jack Pine Stand
• Orono Bog
• Passadumkeag Marsh and Boglands
• Penney Pond-Joe Pond Complex

MARYLAND

• Battle Creek Cypress Swamp
• Belt Woods
• Cranesville Swamp Nature Sanctuary
• Gilpin's Falls
• Long Green Creek and Sweathouse Branch
• Sugarloaf Mountain

MASSACHUSETTS

• Acushnet Cedar Swamp
• Bartholomew's Cobble
• Cold River Virgin Forest
• Fannie Stebbins Refuge
• Gay Head Cliffs
• Hawley Bog
• Lynnfield Marsh
• Mount Greylock Old Growth Spruce
• Muskeget Island
• North and South Rivers
• Poutwater Pond

MICHIGAN

• Black Spruce Bog Natural Area
• Dead Stream Swamp
• Dukes Research Natural Area
• Grand Mere Lakes
• Haven Hill State Natural Area
• Newton Woods
• Porcupine Mountain
• Roscommon Virgin Pine Stand
• Strangmoor Bog
• Toumey Woodlot
• Warren Woods Natural Area

MINNESOTA

• Ancient River Warren Channel
• Cedar Creek Natural History Area-Allison Savannah
• Itasca Natural Area
• Lake Agassiz Peatlands Natural Area
• Keeley Creek Natural Area
• Lac La Croix Research Natural Area
• Pine Point Research Natural Area
• Upper Red Lake Peatland

MISSISSIPPI

• Bienville Pines Scenic Area
• Chestnut Oak Disjunct
• Green Ash-Overcup Oak-Sweetgum Research Natural Areas
• Harrell Prairie Hill
• Mississippi Petrified Forest

MISSOURI

• Big Oak Tree
• Carroll Cave
• Cupola Pond
• Golden Prairie
• Grand Gulf
• Greer Spring
• Maple Woods Natural Area
• Maramec Spring
• Onondaga Cave
• Mark Twain and Cameron Caves
• Marvel Cave
• Pickle Springs
• Taberville Prairie
• Tucker Prairie
• Tumbling Creek Cave
• Wegener Woods

MONTANA

• Bridger Fossil Area
• Bug Creek Fossil Area
• Capitol Rock
• Cloverly Formation Site
• Glacial Lake Missoula
• Hell Creek Fossil Area
• Medicine Lake Site
• Middle Fork Canyon
• Red Rock Lakes National Wildlife Refuge
• Square Butte

NEBRASKA

• Ashfall Fossil Beds
• Dissected Loess Plains
• Fontenelle Forest
• Nebraska Sand Hills
• Valentine National Wildlife Refuge

NEVADA

• Hot Creek Springs and Marsh
• Ichthyosaur Site (Berlin-Ichthyosaur State Park)
• Lunar Crater
• Ruby Marsh
• Timber Mountain Caldera
• Valley of Fire

NEW HAMPSHIRE

• East Inlet Natural Area
• Floating Island
• Franconia Notch
• Heath Pond Bog
• Nancy Brook Virgin Spruce Forest and Scenic Area
• Madison Boulder
• Mount Monadnock
• Pondicherry Wildlife Refuge
• Rhododendron Natural Area
• Spruce Hole Bog
• White Lake Pitch Pine

NEW JERSEY

• Great Falls of Paterson-Garrett Mountain
• Great Swamp (Great Swamp National Wildlife Refuge)
• Manahawkin Bottomland Hardwood Forest
• Moggy Hollow Natural Area
• Palisades of the Hudson
• Pigeon Swamp
• Riker Hill Fossil Site
• Stone Harbor Bird Sanctuary
• Sunfish Pond
• Troy Meadows
• William L. Hutcheson Memorial Forest

NEW MEXICO

• Bitter Lake Group
• Border Hills Structural Zone
• Bueyeros Shortgrass Plains
• Fort Stanton Cave
• Ghost Ranch
• Grants Lava Flow
• Kilbourne Hole
• Mathers Research Natural Area
• Mescalero Sands South Dune
• Ship Rock
• Torgac Cave
• Valles Caldera

NEW YORK

• Bear Swamp
• Bergen-Byron Swamp
• Big Reed Pond
• Crazy Fossil Reef
• Deer Lick Nature Sanctuary
• Dexter Marsh
• Ellenville Fault-Ice Caves
• Fall Brook Gorge
• Fossil Coral Reef
• Hart's Woods
• Hook Mountain and Nyack Beach State Park
• Iona Island Marsh
• Ironsides Island
• Lakeview Marsh and Barrier Beach
• Long Beach, Orient State Park
• McLean Bogs
• Mendon Ponds Park
• Mianus River Gorge
• Montezuma Marshes
• Moss Island
• Moss Lake Bog
• Oak Orchard Creek Marsh
• Palisades of the Hudson
• Petrified Gardens
• Round Lake
• Thompson Pond
• Zurich Bog

NORTH CAROLINA

• Bear Island
• Goose Creek State Park Natural Area
• Green Swamp
• Long Hope Creek Spruce Bog
• Mount Jefferson State Natural Area
• Mount Mitchell State Park
• Nags Head Woods and Jockey's Ridge
• Orbicular Diorite
• Piedmont Beech Natural Area
• Pilot Mountain
• Salyer's Ridge Natural Area
• Smith Island
• Stone Mountain

NORTH DAKOTA

• Fischer Lake
• Rush Lake
• Sibley Lake
• Two-Top Mesa and Big Top Mesa

OHIO

• Arthur B. Williams Memorial Woods
• Blacklick Woods
• Brown's Lake Bog
• Buzzardroost Rock-Lynx Prairie-The Wilderness
• Cedar Bog
• Clear Fork Gorge
• Clifton Gorge
• Crall Woods
• Cranberry Bog
• Dysart Woods
• Fort Hill State Memorial
• Glacial Grooves State Memorial
• Glen Helen Natural Area
• Goll Woods
• Hazelwood Botanical Preserve
• Highbanks Natural Area
• Holden Natural Areas
• Hueston Woods
• Mantua Swamp
• Mentor Marsh
• Serpent Mound Cryptoexplosive Structure
• Tinkers Creek Gorge
• White Pine Bog Forest

OKLAHOMA

• Devil's Canyon
• McCurtain County Wilderness Area
• Salt Plains National Wildlife Refuge

OREGON

• Crown Point
• Fort Rock State Monument
• Horse Ridge Natural Area
• John Day Fossil Beds
• Lawrence Memorial Grassland Preserve
• Newberry Crater
• Willamette Floodplain

PENNSYLVANIA

• Bear Meadows Natural Area
• Box Huckleberry Site
• Cook Forest
• Ferncliff Peninsula Natural Area
• Florence Jones Reineman Wildlife Sanctuary
• The Glens Natural Area
• Hawk Mountain Sanctuary
• Hearts Content Scenic Area
• Hemlocks Natural Area
• Hickory Run Boulder Field
• John Heinz National Wildlife Refuge at Tinicum
• Lake Lacawac
• McConnell's Mill State Park
• Monroe Border Fault
• Nay Aug Park Gorge and Waterfall
• Nottingham Park Serpentine Barrens
• Pine Creek Gorge
• Presque Isle
• Reynolds Spring and Algerine Swamp Bogs
• Snyder-Middleswarth Natural Area
• Susquehanna Water Gaps
• Tamarack Swamp
• Tannersville Cranberry Bog
• Tionesta Scenic and Research Natural Areas
• Titus and Wattsburg Bogs

RHODE ISLAND

• Ell Pond

SOUTH CAROLINA

• Congaree River Swamp
• Flat Creek Natural Area and 40 Acre Rock
• Francis Beidler Forest
• John De La Howe Forest
• Saint Phillips Island
• Stevens Creek Natural Area

SOUTH DAKOTA

• Ancient River Warren Channel
• Bear Butte
• Bijou Hills
• Buffalo Slough
• The Castles
• Cathedral Spires and Limber Pine Natural Area
• Cottonwood Slough-Dry Run
• Fort Randall Eagle Roost
• Lake Thompson
• Mammoth Site of Hot Springs
• Red Lake
• Sica Hollow
• Snake Butte

TENNESSEE

• Arnold Engineering Development Center Natural Areas
• Big Bone Cave
• Cedar Glades Natural Area
• Conley Hole
• Cumberland Cavern (Higginbotham and Henshaw Caves)
• Dick Cove
• Grassy Cove Karst Area
• Lost Sea (Craighead Caverns)
• May Prairie
• McAnulty's Woods
• Piney Falls
• Reelfoot Lake
• Savage Gulf

TEXAS

• Attwater Prairie Chicken Preserve
• Bayside Resaca Area
• Catfish Creek
• Cave Without a Name
• Caverns of Sonora
• Devil's Sink Hole
• Dinosaur Valley
• Enchanted Rock
• Ezell's Cave
• Fort Worth Nature Center and Refuge
• Greenwood Canyon
• High Plains Natural Area
• Little Blanco River Bluff
• Longhorn Cavern
• Lost Maples State Natural Area
• Muleshoe National Wildlife Refuge
• Natural Bridge Caverns
• Odessa Meteor Crater
• Palo Duro Canyon State Park
• Santa Ana National Wildlife Refuge

UTAH

• Cleveland-Lloyd Dinosaur Quarry
• Little Rockies
• Joshua Tree Natural Area
• Neffs Canyon Cave

VERMONT

• Barton River Marsh
• Battell Biological Preserve
• Camel's Hump
• Chazy Fossil Reef
• Cornwall Swamp
• Fisher-Scott Memorial Pines
• Franklin Bog
• Gifford Woods
• Lake Willoughby Natural Area
• Little Otter Creek Marsh
• Molly Bog
• Mount Mansfield Natural Area

VIRGINIA

• Butler Cave-Breathing Cave
• Caledon Natural Area
• Charles C. Steirly Natural Area
• Grand Caverns
• Great Dismal Swamp
• Luray Caverns
• Montpelier Forest
• Rich Hole (George Washington National Forest)
• Seashore Natural Area
• Virginia Coast Reserve

WASHINGTON

• Boulder Park and McNeil Canyon Haystack Rocks
• Davis Canyon
• Drumheller Channels
• Ginkgo Petrified Forest
• Grande Coulee
• Grande Ronde Feeder Dikes
• Grande Ronde Goosenecks
• The Great Gravel Bar of Moses Coulee
• Mima Mounds
• Nisqually Delta
• Point of Arches
• Rose Creek Preserve
• Sims Corner Esker and Kame Complex
• Steptoe and Kamiak Buttes
• Umtanum Ridge Water Gap
• Wallula Gap
• Withrow Moraine and Jameson Lake Drumlin Field

WEST VIRGINIA

• Big Run Bog (Monongahela National Forest)
• Blister Run Swamp (Monongahela National Forest)
• Canaan Valley
• Cathedral Park
• Cranberry Glades Botanical Area
• Cranesville Swamp Nature Sanctuary
• Fisher Spring Run Bog
• Gaudineer Scenic Area
• Germany Valley Karst Area
• Greenville Saltpeter Cave
• Lost World Caverns
• Organ Cave System
• Shavers Mountain Spruce-Hemlock Stand (Monongahela National Forest)
• Sinnett-Thorn Mountain Cave System

WISCONSIN

• Abraham's Woods
• Avoca River-Bottom Prairie
• Baraboo Range
• Bose Lake Hemlock Hardwoods
• Cave of the Mounds
• Cedarburg Bog
• Chippewa River Bottoms
• Chiwaukee Prairie
• Finnerud Forest Scientific Area
• Flambeau River Hemlock-Hardwood Forest
• Kakagon Sloughs
• Kickapoo River Natural Area
• Moquah Barrens Research Natural Area
• Point Beach Ridges
• Ridges Sanctuary-Toft's Point-Mud Lake Area
• Spruce Lake Bog
• Summerton Bog
• Wyalusing Hardwood Forest

WYOMING

• Big Hollow
• Como Bluff
• Crooked Creek Natural Area
• Red Canyon
• Sand Creek
• Two Ocean Pass