Ennis Big Sky Airport (KEKS), Montana
Landing essentials
Whether you can land, whether you can refuel, and how customs works here.
Overview
Ennis Big Sky Airport, KEKS, is a public-use, non-towered field in southwest Montana serving Ennis and the surrounding Madison Valley. Its single 7,600-foot paved runway and Jet A availability support business aviation traffic that FAA TFMSC data classifies as ops tier 1, with 817 of its 902 annual operations attributed to business aviation in 2025. The airport lies roughly 32 nautical miles from the nearest metro area and about 36.7 nautical miles from Bozeman Yellowstone International, the nearest customs-equipped airport.
Runways
Ennis Big Sky Airport has one paved runway, 16/34, 7,600 ft long and 100 ft wide, with an asphalt surface.
Runway geometry from published threshold coordinates. Not for navigation.
Source: FAA Form 5010.
Fuel and airfield services
Ennis Big Sky Airport has Jet A1, Jet A1+ and 100LL available on the field. Fueling is available from 7am to 5pm, daily, and the airport has no control tower.
Source: FAA Form 5010 / NASR.
Customs
Ennis Big Sky Airport does not clear customs. The nearest port of entry is Bozeman Yellowstone International (KBZN), 37 NM away.
Source: CBP list of ports of entry.
Business aviation traffic
Ennis Big Sky Airport recorded 817 business aviation movements in 2025. Traffic peaks in August. Business aviation traffic at KEKS concentrates heavily in the summer months, peaking in August with 181 operations against fewer than 25 in each of the slowest winter months.
Business jet movements, FAA TFMSC count. Peak month August, 181 movements in 2025.
Source: FAA TFMSC, business jet movements, 2025.
Climate
Ennis Big Sky Airport averages 7.1 days above 90°F in July, 28.4 freeze days in January and 2.7 snow days in December. July is the warmest month, with average highs of 82.8°F, and December the coldest, at 33.2°F.
Weather station is 4.7 NM from the field. Some values are estimated by the agency. 1991–2020 climate normals.
Source: NOAA NCEI.
Operating constraints
Ennis Big Sky Airport has published operating constraints in three categories: access, runway notes and other notes.
For clearance delivery, contact Big Sky Approach; if unable, contact Salt Lake Center.
Runway 16/34 medium intensity runway lighting is pilot-activated via CTAF. PAPI systems for both runway 16 and runway 34 operate continuously.
Runway 16/34 has distance markers positioned at 1,020 feet from each end.
Airfield surface conditions are unmonitored between 1700 and 0700.
Service is available after hours.
Credit card fueling is available after hours.
Type 1 de-icing fluid is available.
This is a cold temperature airport. Altitude correction is required at or below -24C.
Source: FAA Chart Supplement.
Nearby airfields
Ennis Big Sky Airport has five airfields within 42 NM. The closest is Ruby Valley Field (KRVF), 31.65 NM northwest.
Part of the Bozeman and Big Sky area.
Source: Skystar calculation from official coordinates.
Skystar at KEKS
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 KEKS.
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
What runway does KEKS offer for business aviation arrivals?
Ennis Big Sky Airport, KEKS, has a single paved runway, 16/34, measuring 7,600 feet by 100 feet with an asphalt surface. That length accommodates most midsize and super-midsize jet operations under normal weight and density altitude conditions. The airport sits at a field elevation of 5,433 feet, which operators should factor into performance planning given the terrain around Ennis, Montana. There is no parallel or crosswind runway, so pilots should plan around the 16/34 orientation for prevailing wind conditions.
Is there fuel available at KEKS outside staffed hours?
Yes, Ennis Big Sky Airport provides after-hours credit card fueling for both 100LL and Jet A grades, listed as A1 and A1+ in airport data. Staffed hours run 0700-1700 daily, and the field remarks note that service is available after those hours through the card system. De-icing type 1 is also available at KEKS. Surface condition monitoring, however, is not maintained between 1700 and 0700, so pilots operating outside staffed hours should confirm conditions independently before arrival or departure.
Where is the nearest customs facility to KEKS?
The nearest customs airport to Ennis Big Sky Airport, KEKS, is Bozeman Yellowstone International, KBZN, located approximately 36.7 nautical miles away. KEKS itself has no onsite customs processing listed in airport data. Operators arriving from outside the United States should plan clearance through KBZN or another designated port of entry before proceeding to Ennis. Flight planning should account for the added routing and coordination time required to clear at a separate facility.
How does business aviation traffic at KEKS vary through the year?
Traffic at Ennis Big Sky Airport, KEKS, is concentrated in the summer months according to FAA TFMSC data for 2025. August recorded 181 business aviation operations, the year's peak, with July at 132 and June at 110. By contrast, winter months such as January, November, and December each saw traffic in the low twenties. Of the airport's 902 total annual operations, 817 were business aviation, making KEKS a seasonally driven field with summer as its clear high period.
What cold-weather procedures apply at KEKS?
Ennis Big Sky Airport, KEKS, is designated a cold temperature airport, requiring altitude correction at or below -24C. Pilots flying published instrument procedures at KEKS in these conditions must apply cold temperature altitude corrections to maintain proper obstacle clearance. Climate data for Ennis shows the coldest months, December and January, average around 33 to 34 degrees Fahrenheit for daily highs, with roughly 28 days per month recording temperatures below freezing. Operators should check current temperatures against the -24C threshold before flying any approach procedure at this field.