ZIP code 21770: Green Valley, MD

ZIP code 21770 is in Green Valley (63% of residents) and Monrovia (36%), in Frederick County, Maryland. It is in Maryland's 6th congressional district. Its state senate district is State Senate District 4; its state house district is State Legislative District 4.

7,575residents (2020 Census)

11.4 sq miland area

2cities and towns

1congressional district

3voting precincts

See it on the map All of Maryland

City and county

City or town	Share of ZIP residents
Green Valley	63%
Monrovia	36%

County	Share of ZIP residents
Frederick County	100%

Town or county subdivision	Share of ZIP residents
District 9, New Market	100%

Congressional district

Congressional district	Share of ZIP residents
Maryland's 6th congressional district (MD-06)	100%

Elected officials

Office	Member	Contact	Share of residents
U.S. Representative (MD-06)	April McClain Delaney (D)	202-225-2721	100%
U.S. Senator	Angela D. Alsobrooks (D)	202-224-4524 · contact form	statewide
U.S. Senator	Chris Van Hollen (D)	202-224-4654 · contact form	statewide
State Senator (State Senate District 4)	Bill Folden (R)		100%
Delegate (State Legislative District 4)	April Miller (R)		100%
Delegate (State Legislative District 4)	Barrie Ciliberti (R)		100%
Delegate (State Legislative District 4)	Jesse Pippy (R)		100%

Officials serving now (members of Congress until January 3, 2027). Sources: State legislators: Open States (public domain); Members of Congress: the @unitedstates project, congress-legislators (CC0).

Local government

Green Valley laws: search for the Green Valley, Maryland code of ordinances
Monrovia laws: search for the Monrovia, Maryland code of ordinances
Frederick County website: http://FrederickCountyMD.gov/
Frederick County laws: search for the Frederick County, Maryland code of ordinances

State legislative districts

State senate district	Share of ZIP residents
State Senate District 4	100%

State house district	Share of ZIP residents
State Legislative District 4	100%

Voting precincts

3 voting precincts overlap ZIP 21770. Map them, with each precinct's share of the ZIP's residents.

Get this in your AI agent

Your agent can get these cities, counties, districts and precincts with their shares, and their GeoJSON boundaries, from Boundary Atlas. Add https://atlas-production-d344.up.railway.app/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:

related_geographies(id="us:zcta:21770")

ZIP 21770 here is the Census Bureau's ZIP Code Tabulation Area, which approximates the USPS ZIP Code; PO-box-only ZIPs have none. Districts are the maps in force for the November 3, 2026 election.