FirefinderFire lookouts of the US

Fire lookout · Elmore County, Idaho

Trinity Lookout

Also known as Trinity Peak, Trinity Mountain

A 1922 stone-cabin site with a 1956 L-4 cab on a 10-foot concrete base; staffed in the fire season and on the National Historic Lookout Register since 2020.

Visit & stay

Not rentable. As far as we know, this lookout cannot be booked for overnight stays.

Access

Access unknown

We do not know the access rules. Check with the land manager before you go.

Can you climb it?
Unknown
Road to the top?
Yes, you can drive up
Staffing
Staffed during fire season (as of 2021)

Facts

Status
Standing
Type
Two-story buildingL-4 cab on a 10-foot concrete base (current cab, 1956); site used for a lookout since 1922The design: L-4
Built of
Stone
Height
10 ft (3.0 m)
Elevation
9,434 ft (2,876 m)
Agency
US Forest Service - Boise National Forest
Land
Federal land
Location
Elmore County, Idaho
Coordinates
43.59899, −115.42892
This entry
VerifiedResearched, then checked independently. Updated 8 Oct 2026.
Firefinder id
us-id-trinity

View from the cab

What you see from the cab: every ridge out to about 93 miles, the named peaks in sight, and other fire lookouts within view, worked out from terrain data in your browser.

Downloads about 3.6 MB of terrain data the first time.

Or see what it could see on the map: the ground in its line of sight.

History

Then and now

  1. 1922 BuiltFirst lookout on the site: a 12x12 stone cabin with a metal roofSources: nhlr.org, idaholookouts.weebly.com, firelookout.com
  2. No record between 1922 and 1945
  3. 1945 StaffedJanuary 1945 newspaper item says the Pine district used four women as lookouts, one on Trinity MountainSource: idaholookouts.weebly.com
  4. 1955 EventDecember 1955 ground party organized in Boise to reach men who had been in a crash in snow-covered terrain; they apparently spent the night in the lookout stationSource: idaholookouts.weebly.com
  5. 1956 Built'Built' field on NHLR detail pageSource: NHLR register entry
  6. 1956 Replaced by a new structureL-4 cab on a 10-foot concrete base replaced the stone cabin (NHLR, Rex's page and Forest Lookouts give 1956 as the build date)Sources: nhlr.org, idaholookouts.weebly.com, firelookout.com
  7. No record between 1956 and 2020
  8. 2020 Added to the National Historic Lookout RegisterRegistered September 27, 2020 as US 1427, ID 119Sources: nhlr.org, idahofirelookouts.com
  9. TodayStandingIt still stands, as far as our sources know.

Old maps of this spot

USGS topographic maps from the years a lookout stood may show it, often as a small symbol labelled “Lookout”. See the old topo maps around it on the Firefinder map, or find every scanned sheet of this spot on USGS TopoView (click the spot there to list them, with dates and downloads).

Story

Researched 8 Oct 2026, fact-checked.

Trinity Lookout sits on Trinity Mountain in the Boise National Forest, about 40 miles east of Boise in Elmore County, Idaho.1,2 Sources put the summit between 9,434 and 9,451 feet.1,2

A lookout has stood on the mountain since 1922, when a 12-by-12 stone cabin with a metal roof went up.1,3 That cabin was later replaced by an L-4 cab on a 10-foot concrete base.1,3

Sources disagree on when that cab went up. The register, Rex's Fire Lookout Page and Forest Lookouts all date it to 1956.1,3,2 Idaho Fire Lookouts gives 1922 for the current structure, and Keeping Watch records the tower as built in 1922.4,5 This story uses 1956 for the cab and 1922 for the first cabin on the site.

Staffing goes back a long way. A January 1945 newspaper item, quoted by Forest Lookouts, says the Pine district used four women as lookouts, one of them on Trinity Mountain.3 In December 1955 a ground party was organized in Boise to reach men who had been in a crash somewhere in rough, snowy country. An Idaho State Journal item quoted by the same site suggests they passed the night in the lookout station.3

The cab is still standing and in use. The register added the lookout on September 27, 2020, and Idaho Fire Lookouts says it has a fire-detection watch right now.1,4

Keeping Watch says the lookout has seasonal staffing, and the register says it is usually manned during fire season.5,1 Idaho Fire Lookouts lists it as drive-up.4 Because it is a working lookout, do not climb up without permission. Ask the Boise National Forest before you plan a visit.

  1. Trinity Lookout, National Historic Lookout Register, http://nhlr.org/lookouts/us/id/trinity-lookout/ (accessed 2026-10-08). ↩
  2. Trinity Peak Fire Lookout Tower, Rex's Fire Lookout Page, https://www.firelookout.com/id/trinity.html (accessed 2026-10-08). ↩
  3. Trinity Peak, Forest Lookouts, https://idaholookouts.weebly.com/trinity-peak.html (accessed 2026-10-08). ↩
  4. Trinity Peak Lookout, Idaho Fire Lookouts, https://www.idahofirelookouts.com/southern-idaho/trinity-peak-lookout/ (accessed 2026-10-08). ↩
  5. Trinity Peak Lookout, Keeping Watch, University of Idaho Library, https://cdil.lib.uidaho.edu/keeping-watch/items/trinity-peak.html (accessed 2026-10-08). ↩

Photos

Trinity Lookout
Trinity LookoutPhoto: Boise National Forest, via National Historic Lookout Register (nhlr.org) · All rights reserved · source
Ground Cabin - 1940's
Ground Cabin - 1940's (1940)Photo: US Forest Service, via National Historic Lookout Register (nhlr.org) · All rights reserved · source
Photo of Trinity Lookout
Photo: Ron Kemnow Collections, via National Historic Lookout Register (nhlr.org) · All rights reserved · source
Trinity Peak in the 1940s
Trinity Peak in the 1940s (1940)Photo: the U.S. Forest Service, Rex Kamstra, and Mike Warth, via firelookout.com · source
Trinity Peak L.O.
Trinity Peak L.OPhoto: the U.S. Forest Service, Rex Kamstra, and Mike Warth, via firelookout.com · source
Trinity Peak L.O.
Trinity Peak L.OPhoto: the U.S. Forest Service, Rex Kamstra, and Mike Warth, via firelookout.com · source
Trinity Peak lookout house
Trinity Peak lookout housePhoto: the U.S. Forest Service, Rex Kamstra, and Mike Warth, via firelookout.com · source
Trinity Peak in 2020
Trinity Peak in 2020 (2020)Photo: the U.S. Forest Service, Rex Kamstra, and Mike Warth, via firelookout.com · source

Photos keep their own rights and are shown with credit. Is one of these yours? You can ask for a different credit or for removal.

Where sources disagree

We show disagreements between sources instead of quietly picking one. If you know which is right, please tell us.

  • Sources disagree on the year it was built.

    • NHLR: 1956
    • firelookout.com -- Rex Kamstra's Forest Fire Lookout Page: 1922
    • Idaho Fire Lookouts (idahofirelookouts.com): 1922

    Sources give different build years. Often one counts the first lookout on the site and another the structure there now.

Sources

  1. National Historic Lookout Register (NHLR) Gave us: name, location, county, elevation, register numbers, agency, ownership, dates, photos, links National Historic Lookout Register (nhlr.org) · All rights reserved (American Resources, Inc.); facts extracted only, no prose copied. · retrieved 4 Oct 2026
  2. Forest Fire Lookout Association (FFLA) - US lookout lists Gave us: type, status, register numbers, links Forest Fire Lookout Association (firelookout.org) · No licence stated; facts extracted only, no prose copied. · retrieved 8 Oct 2026
  3. firelookout.com -- Rex Kamstra's Forest Fire Lookout Page Gave us: what it is built of, height, staffing, photos, links firelookout.com · No licence stated on the site; facts only (coordinates, elevation, built/destroyed years, design, agency). Photos mirrored with the site's stated credit. · retrieved 4 Oct 2026
  4. Idaho Fire Lookouts (idahofirelookouts.com) Gave us: photos, links idahofirelookouts.com · No licence stated; facts only (coordinates, status/built/destroyed year parsed from each entry's short excerpt). Thumbnail photos mirrored with credit per the project's photo policy. · retrieved 4 Oct 2026
  5. FOREST LOOKOUTS -- western US (Ron Kemnow's weebly sites) Gave us: design Ron Kemnow's Forest Lookouts sites (westlookouts, californialookouts, idaholookouts, montanalookouts, oregonlookouts and washingtonlookouts .weebly.com) · No licence stated; facts only (county, land manager, status word, coordinates where the page's own map widget gives them, township-range-section, height and design hints, links). The site's own newspaper quotes, citations and narrative are not reproduced. · retrieved 8 Oct 2026
  6. Firefinder research Gave us: summary, design, status, agency, staffing, visiting details, dates, links, fact-check Firefinder research (sources cited in the story footnotes) · Our own research notes; each fact cites its source in the lookout's story

More about this lookout elsewhere

Firefinder takes facts (places, dates, numbers) from these sources and writes its own words. See all sources and licences.