All data in mySidewalk has three fundamental characteristics: when, where, and what. This allows users to quickly find answers to the questions that matter most to our communities. In this article, we’ll talk about how mySidewalk handles the “where.”

mySidewalk provides data for 16 different geographies, with 14 sourced from the US Census and 2 (Neighborhoods and City Council Districts) unique to mySidewalk.

Users must select a geography when choosing data in mySidewalk, whether for a map, chart, or callout.

Census geographies have a "Russian-nesting doll" structure, where smaller units fit within larger ones. Blocks fit into Block Groups, Block Groups fit into Census Tracts, Tracts fit into Counties, and Counties fit into States.

Some places cross over boundaries, such as Census Tracts that span multiple zip codes or neighborhoods.

Represents the entire US, including all 50 states and the District of Columbia. US territories are not included.

Represents each individual state and the District of Columbia.

Counties are the primary administrative divisions of states. Exceptions include Louisiana (parishes) and Alaska (boroughs).

Small subdivisions of counties, containing 1,200 to 8,000 people. Updated or split based on population changes in each decennial census.

Subdivisions of Census Tracts, containing 600 to 3,000 people. Each Census Tract has at least one Block Group.

Represents cities or incorporated areas. Unincorporated communities are considered "Places" if classified as Census Designated Places (CDPs). The Census excludes the following from its definition of “place”:

The 435 areas from which members are elected to the U.S. House of Representatives.

Metropolitan areas must have an urbanized area of at least 50,000 people, while Micropolitan areas have urban clusters between 10,000 and 50,000 inhabitants. These areas usually comprise a large or central city and its surrounding areas that are socially and economically dependent on that central area.

These USDOT-produced boundaries:

ZIP Codes in mySidewalk are approximations of mail delivery routes, known as ZIP Code Tabulation Areas (ZCTAs), created by the Census. ZIP Codes are mail delivery routes used by the US Postal Service (USPS) and not actually physical boundaries.

Note: Not all ZIP Codes are represented by a ZCTA. When trying to map data collected by ZIP Code, you could use the UDS Mapper crosswalk files to map the missing zip codes to the ZCTAs. Visit the Census website for more information on how ZCTA boundaries were created.

These are the areas from which members are elected to a state senate or legislative equivalent.

These are the areas from which members are elected to the respective state’s house of representatives or legislative equivalent.

Unified School Districts provide education to children of all school ages in their service areas. If an area doesn't have a USD, it is likely covered by other school district types that mySidewalk does not visualize.

County Subdivisions are the primary divisions of counties and equivalent entities (e.g. boroughs and parishes). They include:

MCDs include areas such as charter townships, reservations, and towns. In 12 states (CT, ME, MA, MI, MN, NH, NJ, NY, PA, RI, VT, and WI), MCDs are the equivalent of Place geographies.

City Council Districts include local government political boundaries such as wards, commission districts, and city council districts. Each district is an area from which members are elected to represent constituencies in local government.

mySidewalk builds the City Council District geography using data from open data portals, local government websites, and boundaries provided directly by customers.

Neighborhoods are informal community boundaries with no formal governmental role or official statistical function. Neighborhoods are often defined by their proximity to landmarks or transportation corridors.

mySidewalk builds the neighborhood geography using data from open data portals, local government websites, and boundaries provided directly by customers.

mySidewalk acquires the majority of geographies from US Census cartographic boundary files. Census geographies are updated annually to align with the most recent 5-year American Community Survey (ACS) estimates.