By Kjel Jones — independent custom-home researcher for St. Anthony and the Fremont County valley floor. Not a builder and not a general contractor. Licensed Idaho real estate agent, LPT Realty.

Published 2026-09-21

The Area of City Impact: the belt around St. Anthony that decides which desk reviews your plans.

Three lines, not one

Most people shopping for ground around St. Anthony know about one line: the city limit. In law there are three, and which one your parcel falls on decides which desk reviews your plans:

Idaho requires the belt around every city: it is where growth is expected but the county still governs, with the city holding defined rights to notice and comment. The plain city-versus-county split is drawn elsewhere on this site, and this page is about the belt itself.

Idaho's Local Land Use Planning Act puts the belt on the map by county ordinance. Under Idaho Code §67-6526, the board of county commissioners adopts, by ordinance, a map identifying the area of impact for each city in the county — after notice and a hearing, and with written notice to every owner of property inside a proposed belt. The statute's legislative finding is blunt about who is in charge there:

“The legislature finds that areas of impact are properly under the jurisdiction of the county because the elected representatives of citizens in areas of impact are county officials, not city officials. While cities should receive notice of, and may provide input on, applications brought to the county in an area of impact, cities do not govern or control decisions on those applications.”

— Idaho Code §67-6526(1)(a), as amended by the 2024 Idaho Legislature, chapter 227. Retrieved 15 September 2026

Notice and input — not control. That sentence is the entire personality of the belt, and everything below is the machinery that follows from it.

The document that draws the belt here

St. Anthony's 2023 Comprehensive Plan, as posted by the city, republishes the city-county agreement as Appendix B: six short code sections, 17.04.010 through 17.04.060. Each carries its own history line — originally enacted as Ordinance No. 2015-01, § 2 (2-26-2015), then repealed and reenacted by Ordinance 2018-02 on 9/13/2018. The plan's narrative traces the arrangement back further:

“The City and County reached an agreement in 2005 to establish this area which identified that the City’s Comprehensive Plan and Subdivision and Zoning Ordinances would be adopted for administering development in this area and so this plan will consider lands in the impact area as well as within the City (see Appendix B).”

— City of St. Anthony 2023 Comprehensive Plan, city-posted PDF (5il.co/2lawu); the agreement is republished as Appendix B at pages 94–98. Retrieved 15 September 2026

One caution belongs in every citation of this material. What the city posts is a republish inside the comprehensive plan, not the standalone signed agreement — the posted PDF's adopting-resolution page still carries a placeholder number, so treat it as a reference copy and get signed instruments from the city clerk and the county clerk.

Who runs the belt: the county desk

The agreement's administration section answers the who question in one sentence, and it has read the same way since the 2018 reenactment:

“The County shall be responsible for the administration and enforcement of the plan, policies, and ordinances within the Impact Area…”

— Area of City Impact agreement, §17.04.020(1), as republished in the City of St. Anthony 2023 Comprehensive Plan, Appendix B (Ord. 2015-01; repealed & reenacted by Ord. 2018-02, 9/13/2018). Retrieved 15 September 2026

The rest of that section sends the belt's permit fees to the county as well. The county's own Building page says the same thing from the other direction — it administers building-code permitting everywhere in its jurisdiction “except within the city limits of St. Anthony.” So the practical answer for a building permit anywhere outside the city limits, belt or no belt: the Fremont County Building Department, whose questionnaire is the paperwork that opens a file — the eleven questions the county asks first are mapped on their own page. The belt changes who advises and which standards attach, not which counter takes your application.

Which rulebook applies — a 2018 answer and a 2024 statute

Here is the part most worth getting right, because the documents disagree across time. The agreement text the city republishes — the version reenacted in 2018 — adopts the city’s rulebook for the belt:

The Idaho Legislature then rewired that default statewide. Effective with the 2024 amendments (chapter 227), the statute now reads:

“The applicable county’s comprehensive plan and zoning and subdivision ordinances shall apply in the area of impact. The county may adopt individual county comprehensive plan and zoning and subdivision ordinance provisions regarding a specific area of impact.”

— Idaho Code §67-6526(4)(e), as amended by the 2024 Idaho Legislature, chapter 227. Retrieved 15 September 2026

Same belt, opposite default:

Both texts are quoted accurately above, each to its own document, and nothing on this site can tell you which one is administering your parcel today. That is a question for both desks, asked in writing. Two more wrinkles belong in that call:

• Citation drift. The agreement's renegotiation clause still cites the statute's old lettering — “Idaho Code 67-6526(d)” — from before the 2024 renumbering.
• The reestablishment deadline. The same 2024 statute ordered every city and county to review and reestablish their areas of impact by December 31, 2025, on pain of the existing boundaries nullifying; whether St. Anthony and Fremont County completed that on paper is not documented in anything the city posts. Confirm rather than assume.

The 300-foot rule for a split parcel

One number in the agreement comes up constantly, because the belt line does not follow parcel lines. Section 17.04.010(3) handles the farm the line cuts through:

“In the case where a property under single ownership is divided by the boundary line of the City of St. Anthony Impact Area, and the line divides such property so that one of both of the parts have a depth of three hundred feet (300’) or less, such part shall be included in the jurisdiction within which the larger portion of the property is located.”

— Area of City Impact agreement, §17.04.010(3), as republished in the City of St. Anthony 2023 Comprehensive Plan, Appendix B. “One of both” is the document’s own wording, reproduced exactly. Retrieved 15 September 2026

In plain terms: a sliver 300 feet deep or shallower goes with the side holding most of the land. Now the caution. This is not the only “300 feet” in the city's documents. The comprehensive plan's public-services chapter separately states, as utilities policy, that new development within 300 feet of existing city sewer lines must generally connect — a different rule that happens to share the number, covered with the water-and-sewer decision. Each 300 belongs to its own document and neither implies the other.

Subdividing in the belt: 45 days, then 15

File a land-use application inside the belt and the agreement runs a two-clock sequence past your file. Every application below is filed with the county — never the city — but the county must put a copy in the city's hands early:

The hearing rules sit on top of the clocks (§17.04.050), as the last column shows. The agreement also keeps itself alive during any renegotiation — either the City Council or the Board of County Commissioners can request renegotiation in writing, a meeting between the two must occur within 30 days of that request, and the existing text governs until it is formally amended or replaced. None of these clocks is the permit-review clock — the state's business-day deadlines are a separate layer, mapped in the ten-business-day statute page.

If you plat inside the belt

The belt's real teeth are subdivision conditions. When the county approves a plat inside the impact area, §17.04.020(5) requires all of the following — the first before the subdivision's first dwelling unit may be occupied, the rest written onto the plat and the agreements:

• A street and utility easement plan that connects into and becomes part of the existing city system, drawn so the land can be re-subdivided to urban densities later, and included on the final plat.
• Sewer and water lines installed to accommodate that future re-subdivision to urban densities.
• Development agreements, as the city requires, in place at approval.
• A certificate on the face of the final plat, executed by the city Public Works Director, attesting that the plat conforms to city infrastructure standards.

Two more rules frame all of it:

• Street standards. City road widths and profiles apply in the belt, and where the county's adopted standards differ, the agreement says “the provision imposing the highest level of improvements shall govern.”
• Addressing. Street names and addresses inside the belt are assigned by the county.

What belongs on a final plat generally, and what it takes to change a recorded one, is covered in the final-plat page and the plat-amendment page; the six-lots-or-fewer shortcut interacts with all of it.

Where the map is — and is not

Everything above describes the belt; the belt itself is a map line you cannot currently get from the city's posted documents:

• The boundary map. The agreement fixes the boundary “on the map attached as ‘Exhibit A’” — and no Exhibit A appears in the posted comprehensive plan.
• The belt zoning map. The 2015 city ordinance map behind the LDR1-through-DC1 designations — also not printed in the posted copy.
• Who holds the line. The county assigns addresses inside the belt and will have the line in its records; the city clerk holds the agreement file.

Until you hold a current map, the honest answer to “am I in the belt?” is a question asked of both desks, in writing, with your parcel number. Do not let a paced-off guess decide which desk reviews your house.

Before you rely on any of this

1. Get the parcel number and the latest recorded plat for the ground — everything downstream keys off them.
2. Ask the Fremont County Planning & Building Department, in writing, whether the parcel sits inside the Area of City Impact — and ask for the map behind the answer.
3. Ask the city clerk the same question, and for the current Exhibit A boundary map and the belt zoning map.
4. If either answer mentions the 2024 statute or a reestablishment, ask which rulebook the county administers in the belt today — its own, or provisions adopted for the belt specifically.
5. Split parcel near the line? Measure both parts against the 300-foot rule before you assume a desk.
6. Subdividing? Price the §17.04.020(5) conditions early — urban-density sewer and water lines come before the first occupancy.
7. Track the clocks: 45 days from filing to the city's copy, 15 days for the city's comment, all before any hearing.
8. When the two desks answer differently, that difference is itself the finding — write it down, date it, keep it.
9. Then call (208) 656-1745 and pressure-test what you were told before you spend on drawings.

Common questions

What is the Area of City Impact around St. Anthony?

A belt of unincorporated county land around the city, drawn under Idaho Code 67-6526, where growth is expected but the county still governs. Inside it the county administers and the city gets defined notice and comment rights. The St. Anthony version is republished as Appendix B of the city's 2023 comprehensive plan.

Who issues building permits inside the Area of City Impact?

Fremont County. Section 17.04.020(1) of the agreement makes the county responsible for administration and enforcement within the Impact Area, and the county's Building page says it permits everywhere except within the city limits of St. Anthony. The city's role is notice and comment, not issuance.

Which zoning applies in the impact area - the city's or the county's?

The documents disagree across time. The 2018 agreement text adopts the city's comprehensive plan and city Titles 16 and 17 for the belt. A 2024 amendment to Idaho Code 67-6526(4)(e) makes the county's plan and ordinances apply instead, unless the county adopts belt-specific provisions. Ask both desks which applies to your parcel today.

What is the 300-foot rule in the impact area agreement?

Section 17.04.010(3): when a single-owned property is split by the belt boundary and one part is 300 feet deep or less, that part follows the jurisdiction holding the larger portion. It is a boundary rule only - a separate 300-foot figure in the comprehensive plan governs sewer connection, and the two must not be confused.

How does the city have a say in what gets built in the belt?

Through a two-clock sequence. Applications are filed with the county, which must send the city a copy at least 45 days before the first public meeting. The city then has 15 days after the next St. Anthony Planning and Zoning Commission meeting following that notice - and before any public hearing - to comment.

How can I find out if my parcel is inside the belt?

Ask both desks, in writing, with your parcel number. The agreement says the boundary is set on an Exhibit A map, but no Exhibit A appears in the comprehensive plan the city posts, and the belt zoning map (a 2015 city ordinance) is not printed there either. The county assigns addresses in the belt and holds the line in its records.

What happens to the agreement when land is annexed into the city?

Section 17.04.010(4) says that upon annexation of any part of the Impact Area into the city, the chapter no longer applies to that annexed area. County administration ends there and the city's desks and rules take over completely.

Is the 2018 agreement still in force?

It is the text the city republishes, but two things argue for confirming its current status: a 2024 statute changed which rulebook governs impact areas statewide, and the same statute ordered every city and county to review and reestablish their areas of impact by December 31, 2025, on pain of nullifying existing boundaries. Whether that reestablishment was completed here is not documented in the city's posted materials.

If I subdivide inside the belt, what extra conditions apply?

Under section 17.04.020(5): a street and utility easement plan tying into the city system on the final plat; sewer and water lines sized for future urban-density re-subdivision, installed before the first dwelling unit is occupied; development agreements as the city requires; and a certificate signed by the city Public Works Director on the face of the final plat.