Snow load · the district nobody names
The Fremont County snow-load district almost nobody names: North Fork Highlands, 115 PSF
Published · every figure below was checked against its primary source on the date shown.
A district hiding in plain sight
Fremont County defines more snow-load districts than almost anyone writes about. The one above Ashton carries a figure a quarter higher than the town’s, and it appears in the same sentence of the same ordinance:
“Section 3. Ground Snow Load: The ground snow load shall be … 115 PSF. for the North Fork Highlands district. 90 PSF. for the Ashton District…”
— Fremont County Ordinance No. 2005-02, Section 3 (county-published PDF, retrieved 13 August 2026)
What 25 PSF of difference means
| District | Ground snow load | Against the Ashton District |
|---|---|---|
| Ashton District | 90 PSF | — |
| North Fork Highlands | 115 PSF | +25 PSF, about 28 percent heavier |
A roof engineered for 115 PSF is not a slightly different roof. It reaches into truss depth and spacing, ridge and bearing members, and sometimes the shape of the building itself — decisions taken at the design stage and painful to revisit afterwards.
Why this catches corridor buyers specifically
- The published material is written for the towns. Search results and cost calculators describe Ashton, so a buyer on higher ground reads numbers meant for somewhere lower.
- The authoritative map is an image. The county’s Snow Load Zone Map carries no searchable text, so it does not surface in a search the way a written figure does.
- Boundaries do not follow addresses. A mailing address in Ashton does not guarantee the parcel sits in the Ashton District.
- It is invisible until it is expensive. Nothing about a lot announces its district; the first time most people meet the question is when an engineer asks.
Settling it, in three steps
- Pull the county’s Snow Load Zone Map and locate the parcel by legal description rather than by mailing address.
- Confirm with the building department on (208) 624-7200, with the parcel number to hand. This is a short call and it is free.
- Put the confirmed figure in the bid documents so every builder and the engineer are designing to the same load — the single most effective way to make bids comparable.
And once the district is settled, there is a second question worth asking, because the district minimum is a floor rather than a recommendation: the University of Idaho’s 2015 statewide study recommends higher figures than the district value for several corridor towns.
Related reading on this site
- The 90 PSF question — where the county minimum and the state study part company
- The 32-inch frost depth — the ordinance figure that does not vary by district
- The county permit path — how to reach the department that settles this
- The builder table — the firms who build on both sides of that line
Common questions
What is the North Fork Highlands snow-load district?
One of the districts Fremont County defines in Ordinance No. 2005-02, carrying a ground snow load of 115 PSF. It sits above Ashton in elevation and is the least-discussed of the county's districts — no builder site and no cost calculator appears to mention it.
How much higher is it than the Ashton District?
Twenty-five PSF. The Ashton District is set at 90 PSF and the North Fork Highlands district at 115 PSF in the same section of the same ordinance, so a lot on the wrong side of that boundary carries a materially heavier engineered roof.
How do I find out which district my lot is in?
Fremont County publishes a Snow Load Zone Map through its document centre, and it is the authority. It is an image with no searchable text, so read it against your legal description and then confirm the answer with the building department on (208) 624-7200.
Why does nobody mention this district?
Most published material about building here is written for the towns, and the district covers higher ground rather than a town centre. That is exactly why it catches people — the material a buyer finds first is written about somewhere else.
What happens if my house was designed to the wrong district?
It is a design problem, and how serious depends on when it is caught. Before plans are engineered it is a conversation; after the roof is framed it is a structural remedy. This is the cheapest possible thing to check early.
Does the frost depth change in this district too?
No. The county's 32-inch minimum frost depth is written as a single countywide figure and does not vary by district. The snow load varies; the footing depth does not.
Is 115 PSF the highest district in the county?
No. The ordinance defines districts above this one as well — Fremont County covers a very wide elevation range and the values are drawn to match it. The figure that matters to you is the one for your parcel, which is why the zone map is the document to settle it.
Who should I ask to be certain?
The county building department, on (208) 624-7200, with your parcel number in front of you. A neighbour's recollection of what they built to is not a substitute, particularly near a district boundary.