ZIP Code 91730 · Rancho Cucamonga, California
San Bernardino County · 25,678 counted · 4 districts
Each percentage here is a share of the 25,678 homes counted in ZIP Code 91730, not the chance that any one address is in that district. Enrollment follows the street: two houses on opposite sides of the same road can be in different districts, and only the district office can say which.
The districts named for the early grades in ZIP Code 91730, Rancho Cucamonga, California are not the districts named for high school, and the set changes in both directions: 1 district arrives for high school that no elementary answer names, and 3 run the early grades and stop. 4 districts hold the 25,678 homes counted here between them, and Chaffey Joint Union High is the largest by homes. The area sits in San Bernardino County, California.
Three districts share the early grades
3 districts hold a measurable share of ZIP Code 91730 at this level. Central Elementary is the largest with 15,071 homes; the smallest of them holds 3,431 homes. Central Elementary, Cucamonga Elementary and Etiwanda Elementary are named here for grade school and not for high school.
Every track below is 35 cells long and stands for all 25,678 homes counted in ZIP Code 91730, so one cell is 734 homes, rounded to the nearest whole cell. Cells lit solid are the homes one district holds, and the unlit cells are the homes held by the other districts in the same list.
- Central Elementary School District15,071 of 25,678 homes59%
- Cucamonga Elementary School District7,176 of 25,678 homes28%
- Etiwanda Elementary School District3,431 of 25,678 homes13%
One district covers high school
Chaffey Joint Union High School District is the only high school district named for ZIP Code 91730 at all, and it holds 25,678 of the 25,678 homes counted in the area. Chaffey Joint Union High is named here for high school and not for the early grades.
- Chaffey Joint Union High School District25,678 of 25,678 homes100%
Have a street address?
A ZIP Code names every district that can serve the area; a street address settles which one serves a home. The Census Bureau geocoder takes an exact address and returns its school districts from the current boundary files, free and with no account.
Check an exact address with the Census Geocoder
Then confirm it with the district office. Each district named here, with its NCES district ID, website and phone:
- Chaffey Joint Union High School District NCES ID 0608160 cjuhsd.net (909) 988-8511
- Central Elementary School District NCES ID 0607950 centralsd.net (909) 989-8541
- Cucamonga Elementary School District NCES ID 0616300 cuca.k12.ca.us (909) 987-8942
- Etiwanda Elementary School District NCES ID 0612960 etiwanda.k12.ca.us (909) 899-2451
The set of names changes in both directions
Chaffey Joint Union High is named for high school here and for no elementary grades, and Central Elementary, Cucamonga Elementary and Etiwanda Elementary run the early grades and no more. An address on the wrong street can therefore change district at the change of grade and land in a district that was never part of its elementary answer, while a neighbor two blocks away keeps one name the whole way through.
What one district name costs in 91730
A lookup that answers ZIP Code 91730 with one district name has to pick one of the names below and drop the rest. Measured against the 25,678 homes counted here, for the early grades it is wrong for 10,607 homes and for high school one name is right for every home counted. That is the whole difference between this page and a one-line answer: the same federal file, read to the end instead of to the first row.
The districts that reach into 91730
The districts named above are not alike in size or in reach. Chaffey Joint Union High touches 18 ZIP Code areas in all and holds 25,678 homes inside this one; Central Elementary touches 2 areas. Not one of them is ever the only district in a ZIP Code area anywhere in the country: every postal area they touch, they share with somebody.
- Chaffey Joint Union High School District25,678 of 25,678 here · 18 ZIP areas in all
- Central Elementary School District15,071 of 25,678 here · 2 ZIP areas in all
- Cucamonga Elementary School District7,176 of 25,678 here · 6 ZIP areas in all
- Etiwanda Elementary School District3,431 of 25,678 here · 6 ZIP areas in all
Where Central Elementary goes from here
Central Elementary School District runs kindergarten through grade 8, and it shares both ZIP Code areas it touches with neighbors and is the only district in neither. Inside its own boundary it holds 15,266 homes over 6 square miles; the part of it counted in ZIP Code 91730 is 15,071 of those. The district it shares the most postal ground with is Chaffey Joint Union High School District, across 2 ZIP Code areas. Its thinnest measured foothold is elsewhere: in ZIP Code area 91786 it holds 195 of 20,352 homes, or 1.0% of them.
How 91730 compares in California
Across California the boundary file names more than one district in 996 of the 1,788 ZIP Code areas it names a district for, 56% of them, and 3 areas in the state have no high school district named for part of their homes. Counting the districts named at either level, 150 areas in California name more than this ZIP Code does and 1,489 name fewer. Nationally more than one district is named in 53% of 33,555 areas.
Look up 91730 again, or look up another ZIP Code
The lookup holds every ZIP Code area in the country with homes in it, including the ones with no page of their own. Opening it at 91730 recomputes the same 25,678 homes from the same snapshot, and typing five other digits answers for somewhere else. No server is asked for the answer: the whole index travels with the lookup page itself.
What to do next
Ask the district office to confirm your street address: look on its site for a school locator, a find my school tool or an attendance zone map, or call the office.
A ZIP Code is a set of mail delivery routes, not a boundary: one district covers every home counted in 91730, and even then the street is what enrolls a child, because magnet, charter and choice programs ignore the boundary entirely.
District websites and phone numbers here come from the NCES Common Core of Data directory, 2024-25 school year, filed under the same district ID as the Census boundary files. Where it lists no usable website, none is printed rather than guessed.
What this site can hand you instead:
If a house purchase depends on the answer, ask the district itself for written confirmation of that exact address. A listing is not a district record, and neither is this page.
Where these numbers come from
The homes were counted in the 2020 Census and the district lines are the 2026 boundary file, so a fast-growing area may have changed since; ZIP Codes here are the Census Bureau's ZIP Code Tabulation Areas; a share is a share of homes, not the chance that one address is in a district; and a district is not a school attendance zone. Every source, file and caveat is on the method page.