The US Fish and Wildlife service makes a number of digital spatial data products available to the public for free download. The data sets accessible for each State are for larger scale data (1:24:000 up to 1:500,000). Most of these datasets are providedas ArcView SHP or E00 coverages.
By clicking on a State, you will then be presented with a number of available dataporducts including; data created by or maintained by the U.S. Fish and Wildlife Service as well as links to the metadata and data where possible. Data from other agencies is shown provided. NWI data downloads are provided in Arc/Info export or DLG formats and arranged by 1:250,000 quads.
To access and download 1:100K USGS DLG data, please select a State on the map below.
Note: The image used to create this map was provided by the USGS
The FWS is constantly updating existing paper maps to NAD83 digital data. For a list of their progress, please Click Here
Need help deciphering NWI map codes? No problem… Try Here. Finally, for information and meta-data Click Here.
For a diagram that easily explains the NWI map codes, please see the reference diagrom provided below.
WETLANDS AND DEEPWATER HABITATS CLASSIFICATION SYSTEM SUBSYSTEM CLASS SUBCLASS |- RB=Rock Bottom 1=Bedrock | 2=Rubble | |- UB=Unconsolidated Bottom 1=Cobble-Gravel | 2=Sand | 3=Mud | 4=Organic | |-- 1=SUBTIDAL----|- AB=Aquatic Bed 1=Algal | | 3=Rooted Vascular | | 5=Unknown | | Submergent | | | |- RF=Reef 1=Coral | | 3=Worm | | | |- OW=Open Water/Unknown Bottom (used on older | maps) M=MARINE--------| | | | |- AB=Aquatic Bed 1=Algal | | 3=Rooted Vascular | | 5=Unknown | | Submergent | | | |- RF=Reef 1=Coral |-- 2=INTERTIDAL--| 3=Worm | |- RS=Rocky Shore 1=Bedrock | 2=Rubble | |- US=Unconsolidated Shore 1=Cobble-Gravel 2=Sand 3=Mud 4=Organic SYSTEM SUBSYSTEM CLASS SUBCLASS |- RB=Rock Bottom 1=Bedrock | 2=Rubble | |- UB=Unconsolidated Bottom 1=Cobble-Gravel | 2=Sand | 3=Mud | 4=Organic | |-- 1=SUBTIDAL----|- AB=Aquatic Bed 1=Algal | | 3=Rooted Vascular | | 4=Floating | | Vascular | | 5=Unknown | | Submergent | | 6=Unknown Surface | | | |- RF=Reef 2=Mollusc | | 3=Worm | | | |- OW=Open Water/Unknown Bottom (used on older | maps) E=ESTUARINE-----| | | | |- AB=Aquatic Bed 1=Algal | | 3=Rooted Vascular | | 4=Floating | | Vascular | | 5=Unknown | | Submergent | | 6=Unknown Surface | | | |- RF=Reef 2=Mollusc | | 3=Worm | | | |- SB=Streambed 3=Cobble-Gravel | | 4=Sand | | 5=Mud | | 6=Organic | | | |- RS=Rocky Shore 1=Bedrock | | 2=Rubble | | |-- 2=INTERTIDAL--|- US=Unconsolidated Shore 1=Cobble-Gravel | 2=Sand | 3=Mud | 4=Organic | |- EM=Emergent 1=Persistent | 2=Nonpersistent | |- SS=Scrub-Shrub 1=Broad-Leaved | Deciduous | 2=Needle-Leaved | Deciduous | 3=Broad-Leaved | Evergreen | 4=Needle-Leaved | Evergreen | 5=Dead | 6=Indeterminate | Deciduous | 7=Indeterminate | Evergreen | |- FO=Forested 1=Broad-Leaved Deciduous 2=Needle-Leaved Deciduous 3=Broad-Leaved Evergreen 4=Needle-Leaved Evergreen 5=Dead 6=Indeterminate Deciduous 7=Indeterminate Evergreen SYSTEM SUBSYSTEM CLASS SUBCLASS |- RB=Rock Bottom 1=Bedrock | 2=Rubble | |- UB=Unconsolidated Bottom 1=Cobble-Gravel | 2=Sand |--1=TIDAL--------| 3=Mud | | 4=Organic | | | |-*SB=Streambed 1=Bedrock | | 2=Rubble | | 3=Cobble-Gravel |--2=LOWER | 4=Sand | PERENNIAL----| 5=Mud | | 6=Organic | | 7=Vegetated | | | |- AB=Aquatic Bed 1=Algal R=RIVERINE------|--3=UPPER | 2=Aquatic Moss | PERENNIAL----| 3=Rooted Vascular | | 4=Floating | | Vascular | | 5=Unknown | | Submergent |--4=INTERMITTENT-| 6=Unknown Surface | | | |- RS=Rocky Shore 1=Bedrock | | 2=Rubble | | | |- US=Unconsolidated Shore 1=Cobble-Gravel |--5=UNKNOWN | 2=Sand | PERENNIAL----| 3=Mud (used on older | 4=Organic maps) | 5=Vegetated | |-**EM=Emergent 2=Nonpersistent | |- OW=Open Water/Unknown Bottom (used on older | maps) |-*STREAMBED is limited to TIDAL and | INTERMITTENT SUBSYSTEMS, and comprises | the only CLASS in the INTERMITTENT SUBSYSTEM. | |-**EMERGENT is limited to TIDAL and LOWER | PERENNIAL SUBSYSTEMS. SYSTEM SUBSYSTEM CLASS SUBCLASS |- RB=Rock Bottom 1=Bedrock | 2=Rubble | |- UB=Unconsolidated Bottom 1=Cobble-Gravel | 2=Sand | 3=Mud | 4=Organic | |-- 1=LIMNETIC----|- AB=Aquatic Bed 1=Algal | | 2=Aquatic Moss | | 3=Rooted Vascular | | 4=Floating | | Vascular | | 5=Unknown | | Submergent | | 6=Unknown Surface | | | |- OW=Open Water/Unknown Bottom (used on older | maps) L=LACUSTRINE----| | | | |- RB=Rock Bottom 1=Bedrock | | 2=Rubble | | | |- UB=Unconsolidated Bottom 1=Cobble-Gravel | | 2=Sand | | 3=Mud | | 4=Organic | | | |- AB=Aquatic Bed 1=Algal | | 2=Aquatic Moss | | 3=Rooted Vascular | | 4=Floating |-- 2=LITTORAL----| Vascular | 5=Unknown | Submergent | 6=Unknown Surface | |- RS=Rocky Shore 1=Bedrock | 2=Rubble | |- US=Unconsolidated Shore 1=Cobble-Gravel | 2=Sand | 3=Mud | 4=Organic | 5=Vegetated | |- EM=Emergent 2=Nonpersistent | |- OW=Open Water/Unknown Bottom (used on older maps) SYSTEM SUBSYSTEM CLASS SUBCLASS |- RB=Rock Bottom 1=Bedrock | 2=Rubble | |- UB=Unconsolidated Bottom 1=Cobble-Gravel | 2=Sand | 3=Mud | 4=Organic | |- AB=Aquatic Bed 1=Algal | 2=Aquatic Moss | 3=Rooted Vascular | 4=Floating | Vascular | 5=Unknown | Submergent | 6=Unknown Surface | |- US=Unconsolidated Shore 1=Cobble-Gravel | 2=Sand | 3=Mud | 4=Organic | 5=Vegetated | |- ML=Moss-Lichen 1=Moss | 2=Lichen | P=PALUSTRINE----------------------|- EM=Emergent 1=Persistent | 2=Nonpersistent | |- SS=Scrub-Shrub 1=Broad-Leaved | Deciduous | 2=Needle-Leaved | Deciduous | 3=Broad-Leaved | Evergreen | 4=Needle-Leaved | Evergreen | 5=Dead | 6=Indeterminate | Deciduous | 7=Indeterminate | Evergreen | |- FO=Forested 1=Broad-Leaved | Deciduous | 2=Needle-Leaved | Deciduous | 3=Broad-Leaved | Evergreen | 4=Needle-Leaved | Evergreen | 5=Dead | 6=Indeterminate | Deciduous | 7=Indeterminate | Evergreen | |- OW=Open Water/Unknown Bottom (used on older maps) MODIFIERS |- A=Temporarily Flooded |- B=Saturated |- C=Seasonally Flooded |- D=Seasonally Flooded/Well Drained |- E=Seasonally Flooded/Saturated |- F=Semipermanently Flooded |--Non-Tidal------|- G=Intermittently Exposed | |- H=Permanently Flooded | |- J=Intermittently Flooded | |- K=Artificially Flooded | |- W=Intermittently Flooded/Temporary (used on | | older maps) | |- Y=Saturated/Semipermanent/Seasonal (used on | | older maps) | |- Z=Intermittently Exposed/Permanent (used on | | older maps) WATER REGIME----| |- U=Unknown | | | | | |- K=Artificially Flooded | |- L=Subtidal | |- M=Irregularly Exposed | |- N=Regularly Flooded |--Tidal----------|- P=Irregularly Flooded |-*S=Temporary-Tidal |-*R=Seasonal-Tidal |-*T=Semipermanent-Tidal |-*V=Permanent-Tidal |- U=Unknown | |-*These water regimes are only used in | tidally influenced, freshwater systems. |- 1=Hyperhaline |- 2=Euhaline |--Coastal |- 3=Mixohaline (Brackish) | Halinity-------|- 4-Polyhaline | |- 5=Mesohaline | |- 6=Oligohaline | |- 0=Fresh | | | WATER CHEMISTRY-| | |- 7=Hypersaline |--Inland |- 8=Eusaline | Salinity-------|- 9=Mixosaline | |- 0=Fresh | | | | |--pH Modifiers |- a=Acid for all |- t=Circumneutral Fresh Water----|- i=Alkaline SOIL------------------------------|- g=Organic |- n=Mineral |- b=Beaver |- d=Partially Drained/Ditched SPECIAL MODIFIERS-----------------|- f=Farmed |- h=Diked/Impounded |- r=Artificial Substrate |- s=Spoil |- x=Excavated U = Uplands
(Source: US FWS)
See also the USFWS Wetland MApper Interactive Website & http://www.fws.gov/data/datafws.html