ZIP Code 53066 · Summit, Wisconsin
Waukesha County · 15,955 counted · 4 districts
Each percentage here is a share of the 15,955 homes counted in ZIP Code 53066, 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 53066, Summit, Wisconsin are not the districts named for high school, and the set changes in both directions: one district arrives for high school that no elementary answer names, and another runs the early grades and stops. 4 districts hold the 15,955 homes counted here between them, and Oconomowoc Area is the largest by homes. The largest share leaves 1,668 homes elsewhere: 1,589 homes with Kettle Moraine and Stone Bank and 79 homes in districts too small to name here. Districts holding under half a percent of the homes named at their own level are listed separately below and are not counted in that number.
Three districts share the early grades
3 districts hold a measurable share of ZIP Code 53066 at this level. Oconomowoc Area is the largest with 14,287 homes; the smallest of them holds 667 homes. Stone Bank is named here for grade school and not for high school.
Every track below is 35 cells long and stands for all 15,955 homes counted in ZIP Code 53066, so one cell is 456 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.
- Oconomowoc Area School District14,287 of 15,955 homes90%
- Kettle Moraine School District922 of 15,955 homes5.8%
- Stone Bank School District667 of 15,955 homes4.2%
Below half a percent at the grade school level: Watertown School District and Hartford Joint No. 1 School District hold 79 homes between them, which is why they are counted under the list rather than inside it. A lookup that named them alongside the districts above would be listing a boundary crossing rather than an answer.
Three districts share high school
3 districts hold a measurable share of ZIP Code 53066 at this level. Oconomowoc Area is the largest with 14,287 homes; the smallest of them holds 667 homes. Arrowhead Union High is named here for high school and not for the early grades.
- Oconomowoc Area School District14,287 of 15,955 homes90%
- Kettle Moraine School District922 of 15,955 homes5.8%
- Arrowhead Union High School District667 of 15,955 homes4.2%
Below half a percent at the high school level: Watertown School District and Hartford Union High School District hold 79 homes between them, which is why they are counted under the list rather than inside it. A lookup that named them alongside the districts above would be listing a boundary crossing rather than an answer.
The set of names changes in both directions
Arrowhead Union High is named for high school here and for no elementary grades, and Stone Bank runs 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 53066
A lookup that answers ZIP Code 53066 with one district name has to pick one of the names below and drop the rest. Measured against the 15,955 homes counted here, for the early grades it is wrong for 1,668 homes and for high school it is wrong for 1,668 homes. 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 53066
The districts named above are not alike in size or in reach. Kettle Moraine touches 13 ZIP Code areas in all and holds 922 homes inside this one; Stone Bank touches 3 areas. Oconomowoc Area is the only district in at least one ZIP Code area somewhere in the country, while Arrowhead Union High is never the only one anywhere: every postal area it touches, it shares.
- Oconomowoc Area School District14,287 of 15,955 here · 11 ZIP areas in all
- Kettle Moraine School District922 of 15,955 here · 13 ZIP areas in all
- Arrowhead Union High School District667 of 15,955 here · 8 ZIP areas in all
- Stone Bank School District667 of 15,955 here · 3 ZIP areas in all
Where Oconomowoc Area goes from here
Oconomowoc Area School District runs pre-K through grade 12, and it is the only school district serving 2 of the 11 ZIP Code areas it touches, shares 7 more with neighbors, and holds under half a percent of the homes in the remaining 2. Inside its own boundary it holds 16,317 homes over 111 square miles; the part of it counted in ZIP Code 53066 is 14,287 of those. The district it shares the most postal ground with is Kettle Moraine School District, across 3 ZIP Code areas. Its thinnest measured foothold is elsewhere: in ZIP Code area 53018 it holds 30 of 3,206 homes, or 0.9% of them.
How 53066 compares in Wisconsin
Across Wisconsin the boundary file names more than one district in 600 of the 781 ZIP Code areas it names a district for, 77% of them, and 0 areas in the state have no high school district named for part of their homes. Counting the districts named at either level, 75 areas in Wisconsin name more than this ZIP Code does and 595 name fewer. Nationally more than one district is named in 53% of 33,555 areas.
Look up 53066 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 53066 recomputes the same 15,955 homes from the same snapshot, and typing five other digits answers for somewhere else. Nothing here is fetched from anywhere while you read: the whole index travels with the lookup page itself.
What to do next
Ask the district office to confirm your street address. A district settles that question on its own site: look for a school locator, a find my school tool, or an attendance zone map. Where there is none, ask the office itself.
A ZIP Code is a set of mail delivery routes, not a boundary: 1,668 of the 15,955 homes counted in 53066 sit outside the district holding the most of them, and the line between the two runs along streets rather than around the postal area.
This site links to no district website. None of the federal files it is built from publishes one, and a guessed address is worse than none. It is the district office, not a search engine, that settles an address.
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.
What this cannot tell you
The homes were counted in the 2020 Census and the district lines are the 2026 boundary file. Nothing on this page adjusts one to the other. Where houses have been built or cleared since the count, a share here describes the place as it was counted rather than as it stands today, and in the fastest-growing ZIP Code areas that gap is the largest single source of error on this site.
A share on this page is a share of the homes in the ZIP Code area, not a probability for any particular address. Enrollment is decided by street address, and a district may run magnet, charter or choice programs that ignore the boundary entirely. If a decision depends on the answer, the district office is the only authority; this page shows what the federal boundary files say and when they were published.
A district boundary is not a school attendance zone. This site never says which school an address is assigned to: no current national dataset of attendance zones exists, and the district draws them itself. Nor is anything here endorsed or certified by the Census Bureau; we use their published files, and that is the whole of the relationship.
A ZIP Code is a set of mail delivery routes, not an area. What is mapped here is the Census Bureau's ZIP Code Tabulation Area, the closest published approximation to it. The two are not identical, and a handful of ZIP Codes used only for post office boxes or single buildings have no tabulation area at all.
Where these numbers come from
School district boundaries come from the Census Bureau's Census Geographic Relationship File, current 2026 vintage, which assigns every census block to a unified district or to an elementary and a secondary district. Homes and residents in each block come from the 2020 Census Redistricting Data (PL 94-171), H1_001 and P1_001. The ZIP Code areas come from the same Geographic Relationship File, block to ZIP Code Tabulation Area. District names and grade ranges come from the Census Gazetteer 2025, with 2020 for districts no longer listed.
The place name printed beside a ZIP Code comes from the Census 2020 ZIP Code Tabulation Area relationship files: place, county subdivision and county, taken 2026-09-06. It is a label rather than a measurement: the Census Bureau does not publish which post office a ZIP Code belongs to, so the place named is the one covering the most land inside the area, not the city the Postal Service prints on an envelope.
Everything else on this page — the shares, the counts of districts per ZIP, the comparison between the two grade bands, the rankings — is computed here from those files. The source publishes none of it. Snapshot taken 2026-09-03.