Union County Airport (KMRT), Ohio
Landing essentials
Whether you can land, whether you can refuel, and how customs works here.
Overview
Union County Airport (KMRT) serves Marysville, Ohio, as a public-use, non-towered field roughly 24 nautical miles from the Columbus metro area. The airport recorded 537 business aviation operations in 2025 per FAA TFMSC data, placing it among moderate-traffic general aviation fields in the region. A single paved runway handles most fixed-wing traffic, supplemented by a turf strip for lighter aircraft, and fuel is available around the clock through self-service. Customs clearance is not offered onsite; arriving international flights route through Port Columbus, about 25 nautical miles away.
Runways
Union County Airport has two paved and unpaved runways. The longest, 09/27, is 4,218 ft long and 75 ft wide, with an asphalt surface.
Runways are listed longest first.
Source: FAA Form 5010.
Fuel and airfield services
Union County Airport has Jet A1, Jet A1+ and 100LL 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
Union County Airport does not clear customs. The nearest port of entry is John Glenn Columbus International (KCMH), 25 NM away.
Source: CBP list of ports of entry.
Business aviation traffic
Union County Airport recorded 537 business aviation movements in 2025. Traffic peaks in April. Business aviation traffic at KMRT concentrates in spring and fall months, with April representing the yearly peak and August the low point.
Business jet movements, FAA TFMSC count. Peak month April, 63 movements in 2025.
Source: FAA TFMSC, business jet movements, 2025.
Climate
Union County Airport averages 6.2 days above 90°F in July, 26.1 freeze days in January and 3.2 snow days in January. July is the warmest month, with average highs of 84.9°F, and January the coldest, at 35.0°F.
Weather station is 4.3 NM from the field. Some values are estimated by the agency. 1991–2020 climate normals.
Source: NOAA NCEI.
Operating constraints
Union County Airport has published operating constraints in four categories: access, runway notes, environmental and other notes.
For clearance delivery, contact Columbus Approach.
Runway end identifier lights on runways 09 and 27, PAPI on runways 09 and 27, and medium intensity runway lights on runway 09/27 are pilot-activated via CTAF.
This is the calm wind runway.
The threshold and edges are marked with cones.
The approach ratio is 27:1 to the displaced threshold due to a railroad 20 feet high, located 425 feet from the runway and 260 feet to the right.
Deer, birds, and other wildlife are present on and in the vicinity of the airport.
Fuel is available 24 hours a day through self-service, payable by credit card.
Source: FAA Chart Supplement.
Nearby airfields
Union County Airport has five airfields within 22 NM. The closest is Delaware Municipal / Jim Moore Field (KDLZ), 11.41 NM east.
Part of the Columbus, Ohio area.
Source: Skystar calculation from official coordinates.
Skystar at KMRT
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.
$1,200.00 catering order at KMRT.
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 runways does KMRT (Union County) have?
KMRT, also known as Union County Airport, has two runways. Runway 09/27 is asphalt paved, 4,218 feet long and 75 feet wide, and can accommodate most business aircraft. Runway 08/26 is a 2,522-foot turf strip, 80 feet wide, suited to lighter piston traffic. There is no control tower on the field, so operations follow CTAF procedures.
Is fuel available at Union County Airport?
Union County Airport supplies 100LL and Jet A fuel, listed in the data as A1 and A1+. Fuel is available H24 through self-service via credit card, according to the airport remarks. Attended hours at the field run 0800 to 1700 daily. No fixed base operator staffing outside those hours is indicated in the data.
How does KMRT handle customs clearance for international arrivals?
KMRT does not have customs service onsite. The nearest customs facility is at KCMH, located approximately 25 nautical miles away. Pilots planning international arrivals at Union County Airport should coordinate clearance through that facility in advance. The remarks also direct pilots to contact Columbus Approach for clearance delivery.
What is the seasonal traffic pattern at Union County Airport?
Business aviation traffic at Union County Airport, identifier KMRT, totaled 537 operations in 2025 according to FAA TFMSC data. Monthly counts show a peak in April at 63 operations and a low in August at 32 operations. Traffic fluctuates through the year rather than following a single flat pattern. Dispatchers should expect moderate seasonal variation rather than steady month-to-month volume.