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Mercer County, Missouri

Maps

Landmark Map

Landmark locality map for Mercer County, Missouri
Landmark locality map for Mercer County, Missouri
Map created 15 April 2026.

Interstate HighwayRailroadUS Army Corps of Engineers
US HighwayDepartment of ConservationUS Fish and Wildlife Service
State HighwayDepartment of Natural ResourcesNational Park Service
County HighwayUS Forest ServiceUS Department of Defense

Locator Map

Locator map for Mercer County, Missouri
Locator map for Mercer County, Missouri
Map created 15 April 2026.

Natural Divisions Locality Map

Natural divisions and sections locality map for Mercer County, Missouri
Natural Divisions locality map for Mercer County, Missouri
Map created 15 April 2026.

Ecological Drainage Unit Locality Map

Ecological drainage unit locality map for Mercer County, Missouri
Ecological Drainage Units locality map for Mercer County, Missouri
Map created 15 April 2026.

Major Watersheds Locality Map

Major watersheds locality map for Mercer County, Missouri
Major Watersheds locality map for Mercer County, Missouri
Map created 15 April 2026.

Major Rivers Locality Map

Major rivers locality map for Mercer County, Missouri
Major Rivers locality map for Mercer County, Missouri
Map created 15 April 2026.

Level I Ecoregion Locality Map

Level I Ecoregion locality map for Mercer County, Missouri
Level I Ecoregion locality map for Mercer County, Missouri
Map created 15 April 2026.

Level II Ecoregion Locality Map

Level II Ecoregion locality map for Mercer County, Missouri
Level II Ecoregion locality map for Mercer County, Missouri
Map created 15 April 2026.

Level III Ecoregion Locality Map

Level III Ecoregion locality map for Mercer County, Missouri
Level III Ecoregion locality map for Mercer County, Missouri
Map created 15 April 2026.

Level IV Ecoregion Locality Map

Level IV Ecoregion locality map for Mercer County, Missouri
Level IV Ecoregion locality map for Mercer County, Missouri
Map created 15 April 2026.

Presettlement Prairie Locality Map

Presettlement prairie locality map for Mercer County, Missouri
Presettlement Prairie locality map for Mercer County, Missouri
Map created 15 April 2026.

Historical Vegetation Map

Historical vegetation map for Mercer County, Missouri
Historical Vegetation map for Mercer County, Missouri
Map created 15 April 2026.

WaterPrairieBarrens / Scrub
ForestWoodlandOpen Woodland

Geology Locality Map

Geology locality map for Mercer County, Missouri
Geology locality map for Mercer County, Missouri
Map created 15 April 2026.

AlluviumSandstoneDolomiteLimestone
ClaySandstone / LimestoneDolomite / LimestoneLimestone / Sandstone
IgneousSandstone / DolomiteDolomite / ShaleLimestone / Shale
Limestone / Sandstone / Shale

Species List

Salamanders (Caudata)

Frogs (Anura)

Lizards (Squamata, "Lizards")

Snakes (Squamata, "Snakes")

Turtles (Testudines)

Collection Summary

Mercer County has a total of 51 valid, non-duplicated collections representing 22 species and 24 localities. There are a total of 18 collectors and 19 collection dates for the county. This results in a total of 21 expeditions for the county, a measure of unique date / collector(s) combinations. The county's earliest collection year is 1938 and its most recent collection year is 2023. The earliest and latest collection dates (independent of earliest and most recent collection years) are April 3 and September 13, respectively. If you have a new record to report for Mercer County, read the New Records section of the FAQ.

Collection Summary by Species

Collection summary for Mercer County by species. Some values are unavailable since some records are represented solely by historical literature reports, which sometimes lack complete collecting data. Click on a species or common name to view more information about that species. Click on column headings to sort by that column.
Species Common Name Localities Collections Collectors Dates Expeditions Earliest Year Latest Year
Acris blanchardi Blanchard's Cricket Frog 2 4 2 2 2 1985 2021
Ambystoma tigrinum Eastern Tiger Salamander 2 8 2 2 2 1978 1978
Anaxyrus americanus American Toad 3 5 3 3 3 1938 1983
Chelydra serpentina North American Snapping Turtle 2 2 3 2 2 2010 2011
Chrysemys picta Western Painted Turtle 1 1 1 1 1 2011 2011
Coluber constrictor North American Racer 1 1 1 1 1 1950 1950
Crotalus horridus Timber Rattlesnake 1 1 2 1 1 2018 2018
Diadophis punctatus Ring-necked Snake 3 3 1 2 2 1982 1983
Dryophytes chrysoscelis Cope's Gray Treefrog 1 3 1 1 1 1998 1998
Lampropeltis calligaster Prairie Kingsnake 2 2 2 2 2 1983 2011
Lithobates blairi Plains Leopard Frog 1 1 1 1 1 1983 1983
Lithobates catesbeianus North American Bullfrog 3 3 2 3 3 1983 2023
Lithobates pipiens Northern Leopard Frog 1 1 2 1 1 2009 2009
Lithobates sphenocephalus Coastal Plains Leopard Frog 2 2 1 2 2 2018 2023
Nerodia sipedon Common Watersnake 1 1 1 1 1 1983 1983
Pantherophis obsoletus Western Ratsnake 1 1 1 1 1 1983 1983
Plestiodon fasciatus Common Five-lined Skink 2 6 2 2 2 1978 1991
Pseudacris crucifer Spring Peeper 1 1 2 1 1 2009 2009
Regina grahamii Graham's Crawfish Snake 1 1 1 1 1 2019 2019
Storeria dekayi DeKay's Brownsnake 1 1 1 1 1 1998 1998
Thamnophis proximus Orange-striped Ribbonsnake 1 1 1 1 1 1983 1983
Thamnophis sirtalis Common Gartersnake 1 1 1 1 1 1983 1983

Potential Species Records

Potential species for Mercer County. Species are listed in descending order of their likelihood of occurrence within the county. Click on a species or common name to view more information about that species. Click on column headings to sort by that column.
Likelihood Species Common Name Rationale Ecoregion / Watershed
2 Pseudacris maculata Boreal Chorus Frog Same Level IV ecoregion, within 5 miles Loess Flats and Till Plains
4 Agkistrodon contortrix Eastern Copperhead Same Level IV ecoregion, within 10 miles Loess Flats and Till Plains
4 Ambystoma texanum Small-mouthed Salamander Same Level IV ecoregion, within 10 miles Loess Flats and Till Plains
4 Carphophis vermis Western Wormsnake Same Level IV ecoregion, within 10 miles Loess Flats and Till Plains
4 Lampropeltis holbrooki Speckled Kingsnake Same Level IV ecoregion, within 10 miles Loess Flats and Till Plains
4 Lampropeltis triangulum Eastern Milksnake Same Level IV ecoregion, within 10 miles Loess Flats and Till Plains
4 Ophisaurus attenuatus Western Slender Glass Lizard Same Level IV ecoregion, within 10 miles Loess Flats and Till Plains
4 Plestiodon septentrionalis Prairie Skink Same Level IV ecoregion, within 10 miles Loess Flats and Till Plains
4 Thamnophis radix Plains Gartersnake Same Level IV ecoregion, within 10 miles Loess Flats and Till Plains
6 Apalone mutica Midland Smooth Softshell Same watershed, within 20 miles Thompson
6 Dryophytes versicolor Gray Treefrog Same Level IV ecoregion, within 20 miles Loess Flats and Till Plains
6 Heterodon platirhinos Eastern Hog-nosed Snake Same Level IV ecoregion, within 20 miles Loess Flats and Till Plains
6 Nerodia rhombifer Northern Diamond-backed Watersnake Same Level IV ecoregion, within 20 miles Loess Flats and Till Plains
6 Opheodrys vernalis Smooth Greensnake Same Level IV ecoregion, within 20 miles Loess Flats and Till Plains
6 Pituophis catenifer Bullsnake Same Level IV ecoregion, within 20 miles Loess Flats and Till Plains
6 Scincella lateralis Little Brown Skink Same Level IV ecoregion, within 20 miles Loess Flats and Till Plains
6 Trachemys scripta Red-eared Slider Same Level IV ecoregion, within 20 miles Loess Flats and Till Plains
6 Tropidoclonion lineatum Lined Snake Same Level IV ecoregion, within 20 miles Loess Flats and Till Plains
6 Virginia valeriae Western Smooth Earthsnake Same Level IV ecoregion, within 20 miles Loess Flats and Till Plains
8 Lithobates clamitans North American Green Frog Same Level IV ecoregion, within 30 miles Loess Flats and Till Plains
8 Terrapene ornata Ornate Box Turtle Same Level IV ecoregion, within 30 miles Loess Flats and Till Plains
8 Terrapene triunguis Three-toed Box Turtle Same Level IV ecoregion, within 30 miles Loess Flats and Till Plains
10 Anaxyrus fowleri Fowler's Toad Same Level IV ecoregion, adjacent county Loess Flats and Till Plains
10 Apalone spinifera Northern Spiny Softshell Adjacent county, same watershed Lower Grand

Checklist

All MOHAP publications are released in portable document format (PDF), an ISO standard. You must download and install a reader (click icon below) to view these documents. A state checklist, including all counties, is available on the publications page.