Geographies in mySidewalk

mySidewalk uses 16 distinct geographies to provide precise data insights.

These include:

• 13 Census geographies,
• 1 US Department of Transportation geography, and
• 2 geographies unique to mySidewalk (Neighborhoods and City Council Districts).

Key Features

• Every dataset in mySidewalk has three characteristics: when, where, and what.

Geography Nesting and Exceptions

Nesting Structure

Some Census geographies follow a nested structure, resembling Russian nesting dolls:

• Blocks → Block Groups → Census Tracts → Counties → States.

Exceptions

Detailed overview of geographies

1. Nation: Represents all 50 U.S. states and the District of Columbia. U.S. territories are excluded.

2. State: Includes all U.S. states and the District of Columbia.

3. County: Covers counties, parishes (Louisiana), and boroughs (Alaska). Exceptions include:

   1. Cities acting as both county and city (e.g., Baltimore, MD).

   2. Areas like parts of Yellowstone National Park not assigned to a county is made into a county.

4. Census Tract: Includes subdivisions of counties housing 1,200 to 8,000 people. This is updated during each decennial census.

5. Block Group: Includes Subdivisions of Census Tracts with 600 to 3,000 residents.

6. Place: Represents incorporated cities or Census Designated Places (CDPs).

   1. This excludes some boroughs, towns, and other Minor Civil Divisions (MCDs) which instead are classified as County Subdivisions.

7. Congressional District: Defined by the 435 U.S. House of Representatives districts.

8. Metropolitan & Micropolitan Areas

   1. Metropolitan: Urbanized areas with ≥50,000 people.

   2. Micropolitan: Urban clusters between 10,000 and 50,000 people.

9. Metropolitan Planning Organizations (MPOs): Regions mandated for transportation planning by the Federal Highway Act.

   1. Represent urbanized areas with populations over 50,000

10. ZIP Code: Approximates USPS delivery routes into boundaries called ZIP Code Tabulation Areas (ZCTAs). Please visit the Census website for more information on how ZCTA boundaries were created.

    1. Note: Not all ZIP Codes are represented by a ZCTA.

    2. When trying to map data collected by ZIP Code, you may have to use a crosswalk file to map the missing zip codes to the ZCTAs.

11. State Senate Legislative District: Areas electing state-level legislative members.

12. State House Legislative District: Areas electing state-level legislative members.

13. Unified School District (USD): Covers all grades in an area unless alternative school district types exist.

14. County Subdivisions: Primary divisions of counties and equivalent entities (e.g. boroughs and parishes). Includes minor civil divisions and unorganized territories.

    1. Minor Civil Divisions (MCDs) in 12 states (CT, ME, MA, MI, MN, NH, NJ, NY, PA, RI, VT, and WI) are the equivalent of Place geographies.

15. City Council Districts (Built by mySidewalk): Represents local political boundaries used to elect council members.

16. Neighborhoods (Built by mySidewalk): Informal community boundaries defined by proximity to landmarks or transport.

Geography Updates and Vintage

Update Frequency

Geographies are annually updated.

Vintage