2 Sep 2025

Watershed Boundary Dataset, 4-Digit Hydrologic Units

The 4-Digit Hydrologic Units, a component of the Watershed Boundary Dataset (WBD), depict the second level hydrologic subdivision of the United States. A 4-digit hydrologic unit includes the area drained by a river system, a reach of a river and its tributaries in that reach, a closed basin(s), or a group of streams forming a coastal drainage area. There are 240 4-digit hydrologic units with an average size of 17,521 square miles (45,378 sq. km.).

2 Sep 2025

Location Affordability Index for Family at AMI

This layer displays the estimated percentage of household income for housing and transportation for a family earning the Area Median Income (AMI). The expected values for housing and transportation are modeled by HUD using data from the US Census Bureau and the US Department of Transportation, including:

  • The average household size for a family earning AMI in the neighborhood
  • The average number of workers, vehicles, and vehicle miles traveled for a family in the neighborhood
  • The average utility and rental costs or average utility and mortgage costs for a housing unit to accommodate the family size above
  • The proportion of housing units that are either rentals or owner-occupied in the neighborhood

Note: The LAI does not predict what families are actually paying to live in a particular area, but rather what a family would pay (either in USD or as a percentage of income) if average or reasonable housing and commuting conditions for a particular neighborhood were achieved.

2 Sep 2025

Drought Severity, 2017-2019

This layer displays the percentage of weeks in Any Drought based on analysis of US Drought Monitor weekly drought data files for years 2017-2019.

2 Sep 2025

Location Affordability Index for Family Below AMI

This layer displays the estimated monthly cost for housing and transportation for a low-income, single-parent family (earning 50% of the Area Median Income). The values for housing and transportation are modeled by HUD using data from the US Census Bureau and the US Department of Transportation, including:

  • The average household size for a single-parent family earning 50% AMI in the neighborhood
  • The average number of workers, vehicles, and vehicle miles traveled for a family in the neighborhood
  • The average utility and rental costs or average utility and mortgage costs for a housing unit to accommodate the family size above
  • The proportion of housing units that are either rentals or owner-occupied in the neighborhood

Note: The LAI does not predict what families earning 50% AMI are actually paying to live in a particular area, but rather what a family would pay (either in USD or as a percentage of income) if average or reasonable housing and commuting conditions for a particular neighborhood were achieved.

2 Sep 2025

Uninsured Population by County

Layer displays information about the insurance status of the population age 0-64. The data are from the 2018 Small Area Health Insurance Estimates, released by the US Census Bureau on April 09, 2020.

2 Sep 2025

Wildfire Perimeters

The layer displays historic wildland fire perimeters. The Geospatial Multi-Agency Coordination group, or GeoMAC, is an internet-based mapping tool originally designed for fire managers to access online maps of current fire locations and perimeters in the U.S. Perimeters are submitted to GeoMAC by field offices and made available to the public. Perimeter data is not the final or official perimeter for any incident and is provided for informational purposes only. The final official perimeter should be obtained from the host unit which can be determined by looking at the Unit ID for any specific fire.

2 Sep 2025

Breast Cancer Screening by County, 2017

This layer displays the percentage of female Medicare beneficiaries age 35 and older that received an annual breast exam or mammogram in the latest report year (2017).

2 Sep 2025

Census 2020 Response Rates by Census Tract (Daily Update)

This layer displays self-response rates from households that have responded to the 2020 Census online, by mail, or by phone. Map data are updated daily to reflect current, cumulative response rates.
Note: this layer uses the planned 2020 census tract boundaries.