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The zoning map gives you a letter. The code tells you what the letter costs.
The map is the easy half. The letter on it is the hard half.
Finding the zoning map for a Fremont County lot takes about two minutes. Understanding what the letter it gives you actually permits takes rather longer, and the gap between those two facts is where most cabin projects get their first unpleasant surprise.
The county's zoning districts are established in Chapter 4 of the Fremont County Development Code, 2011 Edition (Ordinance 2011-04), consolidated through Ordinance 2026-03. The map shows you which district your ground sits in. The code — not the map — tells you what that means.
Start with the parcel, not with the map
A zoning map is only useful once you can point at a specific piece of ground on it, and that means starting with the parcel number rather than with an address. Cabin lots frequently have no address at all until a permit forces one.
- Get the parcel number from the county's property search — both parcel tools and what each one holds.
- Locate that parcel in the county GIS and read the zoning layer, which is a separate layer from the parcel layer.
- Take the district letter to Chapter 4 of the Development Code and read that district's own section, not a summary.
- Check whether an overlay also applies. Overlays sit on top of the base district and add requirements without replacing it.
- Confirm the answer with Planning and Zoning before you offer. Fremont County Courthouse, 151 W 1st North, St. Anthony — (208) 624-7200.
Step four is the one people skip. A parcel can read as a perfectly ordinary residential zone and still carry an overlay that changes what may be built on it.
Fremont County has R1, R2 and R4 — and no R3 at all
This surprises people, including people who have bought land here before. Search the entire 309-page Development Code for “R3” and it does not appear once. The county's residential districts are RUT, R1, R2 and R4. There is no R3 zone in Fremont County, and there never was one in this code.
That matters because the internet is full of guides explaining the difference between R3 and R4 zoning, and none of them is describing this county. Zoning letters are not a national standard. R2 in Fremont County, R2 in Ada County and R2 in another state are three unrelated things that happen to share a label. A guide written about somebody else's R-codes will confidently give you the wrong answer about your own lot.
The county's full set of base districts:
| District group | Zones the code establishes |
|---|---|
| Rural | RB Rural Base · RC Rural Conservation · RL Rural Living |
| Residential | RUT Rural Urban Transition · R1 Residential Estate · R2 Residential Low Density · R4 Residential Medium Low Density |
| Commercial | LO Limited Office · C1 Neighbourhood · C2 Community · C3 Regional |
| Industrial | IT Technological · M1 Limited · M2 General |
| Other base zones | AG Agriculture · Public Facilities |
| Overlays and districts | Rural Mixed Use (RMU) · Rural Village District (RVD), plus the overlay districts of section 4.17 |
“For the purpose of this Ordinance, the unincorporated territory of Fremont County is divided into the zoning base districts established in this chapter… Changes to the Zoning Districts established in this chapter shall be by amendment.”
— Fremont County Development Code, 2011 Edition (Ordinance 2011-04), sections 4.11 and 4.12. Consolidated through Ordinance 2026-03. Retrieved 1 September 2026
The code is a 2011 edition carrying amendments through Ordinance 2026-03, and Table 4.2 itself was amended by Ordinance 2022-01. A printed copy from a few years ago is not the operative document, which is why the consolidated version is the one to read.
Most Island Park cabin ground sits in the rural group rather than the residential group, which is a distinction worth establishing early because the two groups are dimensioned by different tables.
What the residential districts actually require
Table 4.2 of the Development Code sets the dimensional standards for the residential districts. These are the numbers that decide where a building can physically sit on a residential-zoned lot.
| Dimensional standard | RUT | R1 | R2 | R4 |
|---|---|---|---|---|
| Roadway frontage (feet) | 250 | 100 | 85 | 60 |
| Any property line on an arterial or collector street | 30 | 30 | 30 | 25 |
| Front property line on a local street or private road | 25 | 25 | 25 | 20 |
| Interior side property line | 25 | 10 | 5 per storey | 5 |
| Side property line on a local street or private road | 20 | 20 | 20 | 20 |
| Rear property line | 25 | 20 | 20 | 15 |
| Maximum coverage | 50% | 50% | 50% | n/a |
| Maximum height, single family (feet) | 30 | 30 | 30 | 30 |
| Maximum height, accessory structures (feet) | 25 | 25 | 25 | 25 |
Two rows deserve attention. RUT demands 250 feet of roadway frontage — two and a half times R1's requirement and more than four times R4's — which quietly rules out a great many narrow parcels. And R2's interior side setback is five feet per storey, not a flat five feet, so a two-storey cabin needs ten and a three-storey needs fifteen. That is a design constraint, not a siting one, and it is easier to solve on paper than after the foundation is in.
The code adds two conditions that apply throughout. Setback distance is measured from the edge of the right-of-way; where that edge is unknown, you measure from the roadway centreline out to half the overall right-of-way width as provided by the county Public Works Director. And a lot on the corner of two roads must meet the required setback along both frontages, which is how a corner lot loses more buildable area than its acreage suggests. Coverage above 25,000 square feet needs a special use permit, and so does exceeding the height limits.
The map does not tell you what you may build
A district letter is a pointer, not a permission. Three things sit between the map and a build, and none of them is on the map:
- The use table. Fremont County's code permits only what its base district tables name, and anything unlisted is prohibited unless the Administrator makes a formal equivalence finding — which is a genuinely unusual way round and worth understanding on its own terms.
- Recorded covenants. On platted Island Park subdivisions the CC&Rs and an architectural committee frequently bind harder than the county does, and the county does not enforce them.
- Physical constraints. Water setbacks, wetlands, snow load and septic feasibility decide the buildable envelope inside whatever the zone allows — starting with how close to the water you may build.
A tiny home is the clearest example of the gap. Whether one is allowed is not answered by the zoning letter; it is answered by whether the use appears in that district's table, whether the structure meets the adopted building code, whether a septic system can serve it, and whether the covenants on the plat permit it. Four questions, four different documents, and the map answers none of them.
Zone boundaries themselves can move, too. Amendments to the districts established in Chapter 4 are made by ordinance, so a map is accurate as of the day it was drawn and the code as consolidated is the thing to check against.
Common questions
Where do I find the Fremont County, Idaho zoning map?
Through the county GIS, reading the zoning layer against your parcel. Start by getting the parcel number from the county's property search, because cabin lots often have no street address until a permit forces one to be assigned.
What is R1 zoning in Fremont County, Idaho?
R1 is the Residential Estate zone. Under Table 4.2 it requires 100 feet of roadway frontage, 30 feet from any property line on an arterial or collector street, 25 feet from a front property line on a local street, 10 feet from an interior side line and 20 feet from the rear, with 50 percent maximum coverage.
What is R2 zoning in Fremont County, Idaho?
R2 is Residential Low Density. It requires 85 feet of roadway frontage, and its interior side setback is five feet per storey rather than a flat five feet — so a two-storey building needs ten feet and a three-storey needs fifteen.
What is the difference between R3 and R4 zoning in Fremont County?
There is no R3 zone in Fremont County. The word R3 does not appear anywhere in the 309-page Development Code. The county's residential districts are RUT, R1, R2 and R4, so any guide comparing R3 with R4 is describing a different jurisdiction.
Do zoning letters mean the same thing everywhere?
No. Zoning codes are local, and R1 or R2 in one county has no necessary relationship to the same label somewhere else. That is the single biggest reason a generic online zoning guide gives the wrong answer about a specific lot.
What are Fremont County's zoning districts?
The rural group is RB, RC and RL. The residential group is RUT, R1, R2 and R4. Commercial is LO, C1, C2 and C3; industrial is IT, M1 and M2. There is also an Agriculture zone, a Public Facilities zone, a Rural Mixed Use overlay and a Rural Village District.
Can I put a tiny home on my property in Fremont County?
The zoning letter alone does not answer that. It depends on whether the use appears in that district's table, whether the structure meets the adopted building code, whether a septic system can serve it, and whether the recorded covenants on the plat permit it — four separate questions in four different documents.
Does the zoning map show covenants?
No. Recorded covenants and any architectural committee on a platted subdivision are private restrictions the county neither shows nor enforces, and on much Island Park ground they are stricter than the county's own rules.
How are setbacks measured in Fremont County?
From the edge of the right-of-way. Where the edge of the right-of-way is unknown, the measurement is taken from the centreline of the roadway out to half the overall right-of-way width, as provided by the county Public Works Director.
Do corner lots have to meet setbacks on both roads?
Yes. The code states that any lot located on a corner of two roads shall meet the required setbacks along both road frontages, which is why a corner lot has less buildable area than its acreage suggests.