Published
Bishop Mountain's fire lookout: 72 feet of CCC steel, 7,810 feet up, on the caldera rim
The only lookout left on the Targhee
Drive the rim road west of US-20 to its dead end and you reach the county’s best view, on legs of gray steel. The Bishop Mountain Lookout is a four-building complex — tower, log cabin, garage, pit toilet — on the summit of an old volcano, and the federal nomination that put it on the National Register of Historic Places in 1986 describes both the ground and the loneliness in one sentence:
“The buildings are situated at an elevation of 7810 1 on the summit of Bishop Mountain, an extinct volcanic vent on the rim of the Island Park Caldera.”
— National Register of Historic Places nomination, Bishop Mountain Lookout (NRIS 86001184, published 23 May 1986). Retrieved 5 October 2026
That rim is the same west edge the caldera page walks you around — Ashton Hill south, Big Bend Ridge and Bishop Mountain west — and the nomination adds what every rim-lot buyer learns by asking: bedrock is basalt, the summit is flat to gently sloping, and precipitation is about 25 inches a year, “falling mostly as snow.” The lookout earned its place on the summit by being the last of its kind:
“The Bishop Mountain Lookout is the only lookout remaining on the Targhee National Forest out of at least nine which once existed.”
— National Register of Historic Places nomination, Bishop Mountain Lookout (NRIS 86001184). Retrieved 5 October 2026
Nine towers once watched this forest. One is left, and it stands two and a half acres of recorded historic ground above the caldera floor.
What the CCC built, 1936 to 1938
The complex is Depression-era work, built by a named company of a named camp. The nomination’s significance section: “The lookout buildings were constructed between 1936 and 1938 by members of Company 2515 of the Civilian Conservation Corps, based at Camp Porcupine (F-405)” — the CCC being the federal work program that put over two million young men to work in the 1930s and built more than 3,400 fire lookouts nationwide. The tower itself is catalogued like a machine, because it was one:
“The lookout tower is a 72’-high gray steel structure with a 7’x7 f enclosed steel cab. It was manufactured by the Aermotor Company of Chicago using their plans MC-39 and MD-79.”
— National Register of Historic Places nomination, Bishop Mountain Lookout (NRIS 86001184). Retrieved 5 October 2026
Beside it stands the cabin the Forest Service’s own page dates precisely: “built in 1938 by the Civilian Conservation Corps and listed on the National Register of Historic Places in 1986” — a 16-by-24-foot one-room log building on the cabin plan the agency recommended for stations used more than 45 days but less than three months. The nomination records “no additions or removals of structures since the lookout complex was built” — which is why the listing holds: the summit still looks like the 1930s left it.
The lookout at a glance
| Fact | Figure | Source |
|---|---|---|
| Summit elevation | 7,810 ft (nomination); the USFS cabin page rounds to 7,800 | NRHP 1986 / USFS |
| Tower | 72-ft gray steel Aermotor, enclosed 7×7-ft cab, plans MC-39 and MD-79 | NRHP 1986 |
| Built | Complex 1936–1938, CCC Company 2515, Camp Porcupine (F-405); cabin dated 1938 | NRHP 1986 / USFS |
| Listing | National Register 1986 (NRIS 86001184), a 2.5-acre historic district | NRHP 1986 |
| The set | Tower, 16×24 log cabin, 14×20 garage, frame pit toilet — nothing added or removed since the 1930s | NRHP 1986 |
| Cabin (when open) | Sleeps four, $30 a night, no water, electricity or indoor plumbing; vault toilet outside; gated road with a combination lock | USFS |
| Water on the summit | None permanent — “water must be hauled in” | NRHP 1986 |
| Climate | About 25 inches of precipitation a year, mostly snow | NRHP 1986 |
The road is the calendar
Read this paragraph as a rim-lot disclosure statement, because it is the same road system your ground answers to. The Forest Service’s access description for the cabin:
“…it is accessible via U.S. Highway 20, then 16 miles of high-clearance gravel roads requiring a four-wheel-drive vehicle from early June to mid-November, or by snowmobile along an ungroomed route from late November to May.”
— U.S. Forest Service, Caribou-Targhee National Forest, Bishop Mountain Cabin (page last updated 14 March 2025). Retrieved 5 October 2026
The facility’s own season line draws it tighter: open all year, but “snowmobile or ski access only Dec. 1st to March 31st.” Count the seasons a rim address actually gets: a wheel season of roughly early June to mid-November — and only in a vehicle built for the gravel — then an oversnow season running to May. A “year-round access” claim on a rim listing needs this exact scrutiny, the same way the winter-access page applies it to the whole region. The ungroomed snowmobile route is the winter door; the county’s groomed 500-mile network is the winter highway elsewhere on the caldera, and the two are different kinds of neighbour.
The cabin is shown closed
Do not plan a night in it yet. The Forest Service page carries a banner reading “Site Closed” (the page was last updated 14 March 2025), and this page prints no friendlier status than that, because there is none to verify: reservations for Forest Service cabins run through Recreation.gov, and the current closure status of this one is a question for the Ashton/Island Park District Office in Island Park, (208) 558-7301. What the closed cabin still tells a buyer is what the summit offers when it does open: one room, two sets of bunks, dishes on the shelf, a combination lock on the gate, and the whole caldera outside the window — the quietest overnight address on the rim.
Why a lookout stands here: the fire frame
The summit’s job was seeing smoke first. The nomination quotes the 1935 regional direction the site had to satisfy — a fire guard who could see “considerable of the country within a 10 to 15-mile radius” — and records that the facility was still being staffed by Bureau of Land Management personnel “during periods of high fire danger”. A tower with a 10-to-15-mile sightline over your timber is the sharpest possible statement of what a rim lot is exposed to: the same forest that makes the view makes the fuel. Two rules pages carry the response, and this one deliberately prints no clearance figure from either:
- The county’s wildfire overlay. What it means when a parcel sits in a wildfire-sensitive area, and what a Wildfire Sensitive Area Plan asks for: ashtonhomebuilders.com/wildfire-sensitive-areas.
- Defensible-space clearing. The zone-and-spacing work a machine actually does in a lodgepole stand, and where the slash goes: islandparkexcavation.com/defensible-space-clearing-island-park.
A rim lot’s fire plan, its access plan and its water plan are the same conversation had three times — the summit’s three permanent facts (view, snow, no water) are the lot’s three permanent facts too.
Building near the rim
- Put the road first: which rim road serves the lot, what it climbs through, and whether early June or mid-November — not the calendar — is when the build season actually opens. Mobilise the dig inside that window, as the foundation-season page argues for gentler ground.
- Ask the water question before the view question: the nomination’s flat statement for this summit — no permanent water, everything hauled — is the warning to test on any rim parcel before you love it.
- Design for the snow the nomination counts: about 25 inches of precipitation a year, mostly snow, is rim weather; the county’s snow-load band for the corridor is the Island Park page’s subject, and the roof answers to it.
- Run the wildfire questions in order — overlay status, defensible space, access for a fire crew — using the two pages above rather than folklore.
- Check the summer neighbours the same as anywhere: black bear, elk and moose are the summit’s residents per the Forest Service page, and the grizzly page covers the country just below.
- Then enjoy the address few can copy: a working 1930s fire tower above the caldera, a dead-end road behind you, and the 10-to-15-mile view that put a lookout there in the first place.
The lookout is the rim’s oldest lesson: up here, the three things that never change are the view, the snow and the absence of water. The CCC solved them with steel, logs and a hauling schedule. A cabin lot solves them with the same three answers — siting, load, and a well — written into the plans before the first truck climbs the gravel.
Common questions
How tall is the Bishop Mountain lookout tower?
72 feet of gray steel with an enclosed 7-by-7-foot cab, manufactured by the Aermotor Company of Chicago on its plans MC-39 and MD-79 — dimensions and maker straight from the National Register nomination.
When was Bishop Mountain Lookout built?
The complex went up between 1936 and 1938, built by members of Civilian Conservation Corps Company 2515 from Camp Porcupine (F-405) on the Targhee. The Forest Service dates the cabin itself to 1938.
Is Bishop Mountain Lookout on the National Register of Historic Places?
Yes — listed in 1986 (NRIS 86001184) as a 2.5-acre historic district, recognized for conservation, architecture and social history, with the Civilian Conservation Corps named as builder.
How high is Bishop Mountain?
The National Register nomination puts the buildings at 7,810 feet on the summit; the Forest Service's cabin page rounds it to 7,800 feet. Either way it stands well above the roughly 6,300-foot caldera floor.
Is Bishop Mountain a volcano?
It is an extinct volcanic vent — a feeder of the great caldera system, not a peak that erupted a cone — sitting on the rim of the Island Park Caldera, on basalt bedrock, per the National Register nomination.
Can you rent the Bishop Mountain cabin?
Not as of the Forest Service page's last update (14 March 2025), which carries a Site Closed banner. When open it is a one-room rental sleeping four at $30 a night, with no water, electricity or indoor plumbing. Current status is a question for the Ashton/Island Park District Office, (208) 558-7301.
How do you get to Bishop Mountain Lookout?
From Ashton, US Highway 20 north 16 miles, west on North Antelope Flat Road #168 for 7.5 miles, then right on Bishop Mountain Road #120 for about 5.4 miles — the road dead-ends at the cabin. That is 16 miles of high-clearance gravel from the highway.
When can you drive to Bishop Mountain?
The Forest Service's window: a four-wheel-drive, high-clearance vehicle from early June to mid-November; after that, snowmobile on an ungroomed route from late November to May, with snowmobile-or-ski access the only access from December 1 to March 31.
Was Bishop Mountain the only fire lookout around?
It is the only one left. The National Register nomination records it as the only lookout remaining on the Targhee National Forest out of at least nine that once existed — and notes it was still staffed by Bureau of Land Management personnel during periods of high fire danger.
What does the lookout mean for a cabin lot on the rim?
Three permanent facts transfer: the access runs on the gravel-and-snowmobile calendar rather than the calendar year, there is no permanent water up there to assume into a well, and the same forest that makes the view is the fuel a fire plan must answer. Start with the wildfire-overlay and defensible-space pages this site links, before the design.