Lemhi County Airport (KSMN), Idaho
Landing essentials
Whether you can land, whether you can refuel, and how customs works here.
Overview
Lemhi County Airport (KSMN) serves Salmon, Idaho, from a single paved runway at 4,044 feet elevation, with mountainous terrain rising nearby. The field is non-towered and handles business aviation traffic that FAA TFMSC data shows concentrated in specific months, with cross-border activity for this Idaho airport tracked as US traffic rather than a foreign-crossing count. Fuel service, including both avgas and Jet A, operates on a set daytime schedule, and the nearest customs clearance point lies well over the border at KBTM in Montana.
Runways
Lemhi County Airport has one paved runway, 17/35, 5,510 ft long and 75 ft wide, with an asphalt surface.
Runway geometry from published threshold coordinates. Not for navigation.
Source: FAA Form 5010.
Fuel and airfield services
Lemhi County Airport has Jet A and 100 available on the field. Fueling is available from 8am to 5pm, daily, and the airport has no control tower.
Source: FAA Form 5010 / NASR.
Customs
Lemhi County Airport does not clear customs. The nearest port of entry is Bert Mooney (KBTM), 77 NM away.
Source: CBP list of ports of entry.
Business aviation traffic
Lemhi County Airport recorded 691 business aviation movements in 2025. Traffic peaks in January, March and October. Business aviation traffic at KSMN is concentrated in the winter and early spring months, particularly January, March, and October, with a noticeable dip during the summer months of July through September.
Business jet movements, FAA TFMSC count. Peak month March, 77 movements in 2025.
Source: FAA TFMSC, business jet movements, 2025.
Climate
Lemhi County Airport averages 12.3 days above 90°F in July, 30.8 freeze days in January and 2.9 snow days in January. July is the warmest month, with average highs of 86.3°F, and January the coldest, at 28.2°F.
Weather station is 3.0 NM from the field. Some values are estimated by the agency. 1991–2020 climate normals.
Source: NOAA NCEI.
Operating constraints
Lemhi County Airport has published operating constraints in two categories: runway notes and other notes.
MIRL for runway 17/35, REIL for runway 17 and runway 35, and PAPI for runway 17 are pilot-activated via CTAF.
Retroreflective reflectors are installed on the parallel taxiway and ramp area.
A mountain rising more than 1,000 feet above field elevation is located 3 miles from the airport.
Taxiway access to the aircraft ramp located on the southeast end of the airport is closed.
This is a cold temperature airport; altitude correction is required at or below -12 degrees Celsius.
Source: FAA Chart Supplement.
Nearby airfields
Lemhi County Airport has two airfields within 42 NM. The closest is Challis (KLLJ), 38.75 NM south.
Source: Skystar calculation from official coordinates.
Skystar at KSMN
We arrange catering, fuel and trip support here. Supplier prices reach you unchanged; our coordination fee sits on its own line.
The same order, priced two ways.
$2,400.00 catering order at KSMN.
Unchanged.
What the kitchen invoices us is what your quote reads.
One line, fixed.
It does not move with the size of the order.
At cost.
Passed on at the exact amount the processor took.
Market practice figures are industry averages, not a specific competitor.
Frequently asked questions
Is there customs service at KSMN?
Lemhi County Airport does not have onsite customs service. The nearest customs facility is at Bert Mooney Airport (KBTM) in Butte, Montana, approximately 77 nautical miles away. Flight crews requiring customs clearance need to plan their arrival through that facility instead. This distance should factor into fuel and routing planning for international arrivals into the Salmon, Idaho area. No customs type or onsite designation is listed for KSMN.
What runway does KSMN offer for business aviation traffic?
Lemhi County Airport has a single runway, 17/35, measuring 5,510 feet long and 75 feet wide with an asphalt surface. This is the only paved runway serving the field, and it matches the airport's listed maximum paved length. Lighting is pilot-controlled, with MIRL on runway 17/35, REIL on both runway 17 and runway 35, and PAPI on runway 17, all activated via CTAF since KSMN is non-towered. Crews should plan lighting activation calls accordingly when operating outside staffed hours.
Does KSMN have any terrain or obstacle considerations nearby?
Yes, Lemhi County Airport has a notable terrain feature close to the field: a mountain rising more than 1,000 feet above field elevation is located just 3 miles out. Combined with the airport's own elevation of 4,044 feet, this creates meaningful terrain awareness requirements for arrivals and departures at KSMN. Crews unfamiliar with the area should review approach and departure procedures carefully given the proximity of high terrain. This is particularly relevant for night or low-visibility operations.
What fuel is available at KSMN?
Lemhi County Airport stocks both 100LL avgas and Jet A fuel. The field's attendance schedule runs all days of the week from 0800 to 1700 local time, which governs when fuel service is staffed. Crews planning arrivals outside these hours should account for the lack of attended fuel service. KSMN's fuel offering supports both piston and turbine business aviation traffic, consistent with its designation as a public-use airport in Salmon, Idaho.
Are there cold weather procedures pilots should know about at KSMN?
Lemhi County Airport is designated a cold temperature airport, requiring altitude corrections at or below -12 degrees Celsius. This is a meaningful consideration given the field's winter climate: January and December average highs sit near 28 to 29 degrees Fahrenheit, with roughly 31 days per month below freezing during those two months. Pilots flying instrument approaches into KSMN during cold months need to apply the appropriate altitude corrections to published minimums. This affects both approach planning and terrain clearance margins given the mountainous surroundings.