Published
Island Park's Main Street: the 34.8-mile city along US-20
The city is the highway
Most cities have a Main Street; Island Park is one. The city runs the length of US-20 through the caldera — past Mack’s Inn, across the Henrys Fork at Coffee Pot, along the reservoir at Last Chance in the south, and up to the Montana line in the north — and its own comprehensive plan measures the whole thing in three numbers:
“The City is 34.8 miles long and ranges from 1,000 feet to 5,000 feet in width.”
— City of Island Park Comprehensive Plan (adopted 23 October 2014). Retrieved 5 October 2026
Thirty-four point eight miles of city. The width is the part that surprises drivers: between 1,000 and 5,000 feet, so in most places the city is the highway, its commercial ribbons, and a strip of forest or meadow behind them — then it ends. The same plan counts 6.77 square miles of city inside a 25-square-mile Area of Impact, and 286 permanent residents (2010) — still, per the plan, Fremont County’s third largest city, behind only St. Anthony and Ashton. Even City Hall’s address is the highway: 3753 N. Highway 20, per the city’s own website footer, 27 miles south of West Yellowstone.
Why it exists: a liquor law
The city was drawn with a bartender’s pen. The plan’s history chapter says it in one sentence — “The City was created in 1947 in response to the State of Idaho’s changes in the liquor laws” — and then fills in the mechanics:
“By 1947 several hospitality and retail businesses had built up along a narrow 36.8 mile stretch of US Highway 20.”
— City of Island Park Comprehensive Plan (2014), Incorporation. Retrieved 5 October 2026
That year the Idaho Legislature wrote new law on liquor by the drink — and the operative provision was jurisdictional, not moral:
“A provision of the law required businesses that sell alcoholic beverages to be licensed and located within incorporated cities or villages.”
— City of Island Park Comprehensive Plan (2014), Incorporation. Retrieved 5 October 2026
A lodge on US-20 outside any city could no longer pour. The businesses’ answer was to become a city, and the boundary logic is the most honest sentence in the document: “The boundaries included all businesses selling alcoholic beverages between Last Chance and the Montana border” — the map was drawn to catch every bar, and nothing that wasn’t one. The county commissioners signed it:
“On May 16, 1947, the county commissioners incorporated the village and appointed a board of trustees to serve until the next election.”
— City of Island Park Comprehensive Plan (2014), Incorporation. Retrieved 5 October 2026
Democracy followed the paperwork. Two years later — “On August 18, 1949, there were 70 registered voters in the village” — and Harvey Schwendiman, the first chairman (mayor), took 57 of the 58 votes cast. The plan closes the story with the fact that matters to anyone buying here today: “Since incorporation, the City boundaries have changed little.” The line drawn in 1947 is substantially the line now.
The boast, measured
The claim on the sign is the city’s own, and this page prints it as exactly that. The plan’s words: “Longest Main Street in America” — and it attributes the saying to civic pride, calling it what residents “proudly boast.” Two things keep the boast honest. First, it is America, not the world, in the city’s own telling; no record-keeping body certifies either ranking. Second, “Main Street” here is US-20 itself — a federal highway that happens to be the only through-street a 34.8-mile city needs; there is no separate street named Main. What the highway actually carries, the plan describes precisely:
“Main Street has significant open space interspersed with lodges, motels, restaurants, lounges, convenience stores, gas stations, tackle shops and recreational vehicle rental businesses”
— City of Island Park Comprehensive Plan (2014). Retrieved 5 October 2026
Read that sentence as a land-use map. The city is not a wall-to-wall resort strip; it is nodes of commerce with real forest and meadow between them, all inside one set of city limits — which is why a “lot in Island Park” can mean a cabin beside a lodge, a cabin behind the trees from a lounge, or a cabin a mile from anything, all at the same address on the same highway.
The ribbon at a glance
| Fact | Figure | Source |
|---|---|---|
| Incorporated | 16 May 1947, by the Fremont County commissioners, as a village | City Comp Plan 2014 |
| Why | State liquor law required by-the-drink sellers to be inside an incorporated city or village | City Comp Plan 2014 |
| Boundary logic | All businesses selling alcoholic beverages between Last Chance and the Montana border | City Comp Plan 2014 |
| Length | 34.8 miles, along a 36.8-mile stretch of US-20 | City Comp Plan 2014 |
| Width | 1,000 to 5,000 feet | City Comp Plan 2014 |
| Area | 6.77 square miles of city; 25 square miles in the Area of Impact | City Comp Plan 2014 |
| Residents | 286 permanent (2010) — the county’s third largest city | City Comp Plan 2014 |
| First mayor | Harvey Schwendiman, 57 of 58 votes, 18 August 1949; 70 registered voters | City Comp Plan 2014 |
| City Hall | 3753 N. Highway 20 — the address is the highway | City website |
A city of guest cabins
The 1947 boundaries drew a resort economy, and the Census has watched it become one almost completely. The plan tracks the share of the city’s houses kept for short-term rental — rent for less than 30 days — across three counts: 75 percent in 2000, 85 percent in 2010, and then:
“According to the 2012 US Census estimate, this use has risen to 89% in the City, and to 85.4% in the Island Park CCD.”
— City of Island Park Comprehensive Plan (2014), Economy and Major Employers. Retrieved 5 October 2026
Nearly nine of every ten houses in the city exist to be rented to visitors — a statistic that explains the ribbon’s rhythm better than any brochure: a summer population that swells with anglers and Yellowstone-bound families, a January that belongs to the locals and the snowmobile economy, and a neighbourhood composition that changes weekly by design. Two practical notes for a buyer. The law around renting a cabin is its own subject — Idaho has since barred counties from requiring short-term rental permits, and the rental-law page owns that answer. And the winter half of the economy runs on the groomed snowmobile network, which the trail page covers — including what living on it means for a homesite.
Inside the line, outside the line
Here is the fact that matters most to a cabin buyer: most of what people call “Island Park” is not in the city. The city is the ribbon along US-20 — 6.77 square miles of it — and nearly everything around it, the 25-square-mile Area of Impact included, is unincorporated Fremont County. A lot’s position relative to that 1947 line decides which jurisdiction’s rules apply, and the answer is not visible from the highway: the city publishes its own development code, the county publishes the code most of this site’s pages walk through, and a parcel a quarter-mile apart can answer to different ones. Which desk reviews an application inside the Area of Impact — and what happens to a parcel the boundary cuts in two — is precisely the Henrys Lake page’s subject, written for the lake country the ribbon runs below; the same question applies anywhere the city line wanders. Settle it in writing before relying on either rulebook.
The city’s own plan also states its preferences for growth inside the line, and a buyer can read them as the neighbourhood’s future: in-fill inside city limits encouraged, new commercial zones discouraged unless need is demonstrated, industrial uses limited, and development steered away from wetlands, steep slopes and wildfire hazard areas — the same sensitivities the caldera page explains from the ground up.
Buying on the ribbon
- Fix the mile marker in your head before the listing does it for you: the south end is Last Chance and the reservoir country the Shotgun page covers; the middle miles carry the river reaches past Mack’s Inn and Coffee Pot; the north end climbs toward the Montana line. Same highway, different neighbours.
- Settle jurisdiction first — city, Area of Impact, or plain county — using the county’s own answer in writing, then apply the right development code to the lot. Everything else in due diligence inherits this answer.
- Walk the node, not just the lot: the plan’s own description — lodges, lounges, convenience stores, RV rental businesses with open space between — tells you whether your nearest neighbour is a bar’s parking lot or a meadow, and August is the month that shows you.
- Ask what the 89 percent means at this address: if the cabins around the lot are weekly rentals, the practical neighbourhood rules — noise, parking, trash — live in how they are managed, not in who owns them.
- Price both seasons: a ribbon lot’s access and income run on the summer-highway and winter-trail calendars, the flip the winter page documents for the whole region.
- Then run the ordinary cabin questions in order — water, septic, access, snow load — exactly as the before-you-build page lays them out, because a 34.8-mile city still builds one cabin at a time.
The Main Street story is the buying story: this city was incorporated by its businesses, for its businesses, along a road — and the lots that make sense today are the ones whose buyers understand what that origin built. A highway with city limits, a boast with a documented basis, and a 1947 line that still decides who reviews your permit: that is Island Park’s Main Street.
Common questions
How long is Island Park's Main Street?
The city measures 34.8 miles long along a 36.8-mile stretch of US Highway 20, per its own comprehensive plan (2014). The popular shorthand of 33 miles rounds it down; the city's own number is 34.8.
Does Island Park have the longest Main Street in the world?
The city's own claim, in its comprehensive plan, is the 'Longest Main Street in America' — described as what residents proudly boast. No record-keeping body certifies a national or world ranking, so the honest form is the city's own words: a boast, and a well-founded one.
Why was the City of Island Park incorporated?
For the drinks. By 1947, businesses had built up along US-20, and a new state law required businesses selling liquor by the drink to be located inside an incorporated city or village. The highway establishments applied to the county commissioners, and the boundaries were drawn to include every business selling alcoholic beverages between Last Chance and the Montana border.
When was Island Park incorporated?
On May 16, 1947, the Fremont County commissioners incorporated the village and appointed a board of trustees. The first election came on August 18, 1949, with 70 registered voters; Harvey Schwendiman, the first chairman (mayor), took 57 of the 58 votes cast.
How wide is the City of Island Park?
Between 1,000 and 5,000 feet, per the city's comprehensive plan. The city encompasses 6.77 square miles inside a 25-square-mile Area of City Impact.
How many people live in Island Park?
The city's comprehensive plan counted 286 permanent residents at the 2010 Census — making it Fremont County's third largest city after St. Anthony and Ashton. The seasonal population is far larger; the plan's economy chapter tracks the city's housing as overwhelmingly visitor-oriented.
Is most housing in Island Park short-term rental?
Yes, by a wide margin. Per the city's plan citing Census figures, 75% of the city's houses were short-term rental in 2000, 85% in 2010, and 89% by the 2012 Census estimate (85.4% in the wider Island Park CCD). What a county may regulate about rentals today is a separate legal question this site covers on its rental-law page.
What does it mean if my lot is inside Island Park city limits?
The city's own development code and permit desk apply, rather than the county's — and the city publishes its own code on its website. Most ground described as 'Island Park' sits outside the ribbon in unincorporated county or the Area of Impact, so the jurisdiction question is worth settling in writing before relying on either rulebook.
Where does Island Park's Main Street start and end?
The 1947 boundaries ran from Last Chance in the south to the Montana border in the north — chosen to include every business selling alcoholic beverages along the way. The plan notes the boundaries have changed little since incorporation.
Why does Island Park look like one long highway strip?
Because that is what was incorporated: the commercial nodes along US-20 plus the ground between them. The plan describes Main Street as significant open space interspersed with lodges, motels, restaurants, lounges, convenience stores, gas stations, tackle shops and RV rental businesses — nodes with forest and meadow between, all inside one set of city limits.