Nonstop flight route between Roundup, Montana, United States and St. Mary's, Alaska, United States:
Departure Airport:
(46°28'30"N by 108°32'35"W)
Arrival Airport:
(62°3'38"N by 163°18'6"W)
Distance from RPX to KSM:
2,365.33 miles (3,806.62 km)
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Jump to:
- About this route
- RPX Airport Information
- KSM Airport Information
- Facts about RPX
- Facts about KSM
- Map of Nearest Airports to RPX
- List of Nearest Airports to RPX
- Map of Furthest Airports from RPX
- List of Furthest Airports from RPX
- Map of Nearest Airports to KSM
- List of Nearest Airports to KSM
- Map of Furthest Airports from KSM
- List of Furthest Airports from KSM
About this route:
A direct, nonstop flight between Roundup Airport (RPX), Roundup, Montana, United States and St. Mary's Airport (KSM), St. Mary's, Alaska, United States would travel a Great Circle distance of 2,365 miles (or 3,807 kilometers).
A Great Circle is the shortest distance between 2 points on a sphere. Because most world maps are flat (but the Earth is round), the route of the shortest distance between 2 points on the Earth will often appear curved when viewed on a flat map, especially for long distances. If you were to simply draw a straight line on a flat map and measure a very long distance, it would likely be much further than if you were to lay a string between those two points on a globe. Because of the relatively short distance between Roundup Airport and St. Mary's Airport, the route shown on this map most likely still appears to be a straight line.
Departure Airport Information:
| IATA / ICAO Codes: | RPX / KRPX |
| Airport Name: | Roundup Airport |
| Location: | Roundup, Montana, United States |
| GPS Coordinates: | 46°28'30"N by 108°32'35"W |
| Area Served: | Roundup, Montana |
| Operator/Owner: | City of Roundup & Musselshell County |
| Airport Type: | Public |
| Elevation: | 3490 feet (1,064 meters) |
| # of Runways: | 2 |
| View all routes: | Routes from RPX |
| More Information: | RPX Maps & Info |
Arrival Airport Information:
| IATA / ICAO Codes: | KSM / PASM |
| Airport Name: | St. Mary's Airport |
| Location: | St. Mary's, Alaska, United States |
| GPS Coordinates: | 62°3'38"N by 163°18'6"W |
| Operator/Owner: | Alaska DOT&PF |
| Airport Type: | Public |
| Elevation: | 312 feet (95 meters) |
| # of Runways: | 2 |
| View all routes: | Routes from KSM |
| More Information: | KSM Maps & Info |
Facts about Roundup Airport (RPX):
- Roundup Airport (RPX) has 2 runways.
- The closest airport to Roundup Airport (RPX) is Billings Logan International Airport (BIL), which is located 46 miles (74 kilometers) S of RPX.
- The furthest airport from Roundup Airport (RPX) is Sir Gaëtan Duval Airport (RRG), which is located 10,535 miles (16,954 kilometers) away in Rodrigues Island, Mauritius.
Facts about St. Mary's Airport (KSM):
- Because of St. Mary's Airport's relatively low elevation of 312 feet, planes can take off or land at St. Mary's Airport at a lower air speed than at airports located at a higher elevation. This is because the air density is higher closer to sea level than it would otherwise be at higher elevations.
- The closest airport to St. Mary's Airport (KSM) is Mountain Village Airport (MOU), which is located only 13 miles (20 kilometers) W of KSM.
- St. Mary's Airport (KSM) has 2 runways.
- The furthest airport from St. Mary's Airport (KSM) is Cape Town International Airport (CPT), which is located 10,494 miles (16,889 kilometers) away in Cape Town, South Africa.
| Rank | Distance & Direction | Airport Name & IATA Code | Airport Location | Further Actions |
| 1 | 46.10 miles (74.19 km) S | Billings Logan International Airport (BIL) | Billings, Montana, United States |     |
| 2 | 59.02 miles (94.99 km) NW | Lewistown Municipal Airport (LWT) | Lewistown, Montana, United States | |
| 3 | 95.49 miles (153.67 km) NE | Jordan Airport (JDN) | Jordan, Montana, United States | |
| 4 | 105.84 miles (170.33 km) WSW | Mission Field (LVM) | Livingston, Montana, United States | |
| 5 | 126.53 miles (203.63 km) E | Miles City Airport (MLS) | Miles City, Montana, United States | |
| 6 | 133.88 miles (215.46 km) WSW | Bozeman Yellowstone International Airport (BZN) | Bozeman, Montana, United States | |
| 7 | 137.05 miles (220.56 km) S | Yellowstone Regional Airport (COD) | Cody, Wyoming, United States | |
| 8 | 139.98 miles (225.28 km) SSE | Sheridan County Airport (SHR) | Sheridan, Wyoming, United States | |
| 9 | 143.48 miles (230.90 km) WNW | Malmstrom Air Force Base (GFA) | Great Falls, Montana, United States | |
| 10 | 150.20 miles (241.73 km) NE | Glasgow International Airport (GGW) | Glasgow, Montana, United States | |
| 11 | 150.36 miles (241.97 km) WNW | Great Falls International Airport (GTF) | Great Falls, Montana, United States | |
| 12 | 153.79 miles (247.50 km) NNW | Havre City-County Airport (HVR) | Havre, Montana, United States | |
| 13 | 163.70 miles (263.45 km) W | Helena Regional Airport (HLN) | Helena, Montana, United States | |
| 14 | 175.30 miles (282.12 km) SW | Yellowstone Airport (WYS) | West Yellowstone, Montana, United States | |
| 15 | 175.96 miles (283.18 km) S | Worland Municipal Airport (WRL) | Worland, Wyoming, United States | |
| Rank | Distance & Direction | Airport Name & IATA Code | Airport Location | Further Actions |
| 1 | 10,534.71 miles (16,953.93 km) SSE | Sir Gaëtan Duval Airport (RRG) | Rodrigues Island, Mauritius | |
| 2 | 10,479.36 miles (16,864.85 km) SSE | Pierrefonds Airport (ZSE) | Saint-Pierre, Réunion | |
| 3 | 10,476.57 miles (16,860.37 km) SSE | Sir Seewoosagur Ramgoolam International Airport (MRU) | Plaisance, Mauritius | |
| 4 | 10,454.31 miles (16,824.54 km) SSE | Roland Garros Airport (RUN) | St Denis, Réunion, France | |
| 5 | 10,433.23 miles (16,790.61 km) SE | Tôlanaro Airport (FTU) | Tôlanaro, Madagascar | |
| 6 | 10,330.91 miles (16,625.95 km) SE | Ampanihy Airport (AMP) | Ampanihy, Madagascar | |
| 7 | 10,261.65 miles (16,514.48 km) SE | Mananjary Airport (MNJ) | Mananjary, Madagascar | |
| 8 | 10,233.41 miles (16,469.03 km) SE | Fianarantsoa Airport (WFI) | Fianarantsoa, Madagascar | |
| 9 | 10,132.24 miles (16,306.22 km) SE | Manja Airport (MJA) | Manja, Menabe, Madagascar | |
| 10 | 10,132.23 miles (16,306.21 km) SE | Andavadoaka Airport (DVD) | Andavadoaka, Toliara province, Atsimo-Andrefana region, Madagascar | |
| 11 | 10,116.24 miles (16,280.48 km) SE | Morombe Airport (MXM) | Morombe, Madagascar | |
| 12 | 10,108.66 miles (16,268.28 km) SE | Toamasino Airport (TMM) | Toamasina, Madagascar | |
| 13 | 10,089.56 miles (16,237.54 km) SE | Ivato International Airport (TNR) | Antananarivo, Madagascar | |
| 14 | 10,066.19 miles (16,199.92 km) SE | Miandrivazo Airport (ZVA) | Miandrivazo, Madagascar | |
| 15 | 10,059.04 miles (16,188.42 km) SE | Sainte Marie Airport (SMS) | Île Sainte-Marie, Madagascar | |
| Rank | Distance & Direction | Airport Name & IATA Code | Airport Location | Further Actions |
| 1 | 12.52 miles (20.15 km) W | Mountain Village Airport (MOU) | Mountain Village, Alaska, United States | |
| 2 | 15.71 miles (25.28 km) ESE | Pilot Station Airport (PQS) | Pilot Station, Alaska, United States | |
| 3 | 43.61 miles (70.18 km) ESE | Marshall Don Hunter Sr. Airport (MLL) | Marshall, Alaska, United States | |
| 4 | 58.95 miles (94.87 km) WNW | Sheldon Point Airport (SXP) | Sheldon Point, Alaska, United States | |
| 5 | 61.02 miles (98.20 km) NW | Alakanuk Airport (AUK) | Alakanuk, Alaska, United States | |
| 6 | 62.90 miles (101.24 km) NW | Emmonak Airport (EMK) | Emmonak, Alaska, United States | |
| 7 | 67.40 miles (108.48 km) N | Kotlik Airport (KOT) | Kotlik, Alaska, United States | |
| 8 | 67.43 miles (108.52 km) ESE | Russian Mission Airport (RSH) | Russian Mission, Alaska, United States | |
| 9 | 75.21 miles (121.04 km) W | Scammon Bay Airport (SCM) | Scammon Bay, Alaska, United States | |
| 10 | 83.21 miles (133.91 km) WSW | Chevak Airport (VAK) | Chevak, Alaska, United States | |
| 11 | 84.72 miles (136.35 km) SSE | Nunapitchuk Airport (NUP) | Nunapitchuk, Alaska, United States | |
| 12 | 85.97 miles (138.35 km) SSE | Kasigluk Airport (KUK) | Kasigluk, Alaska, United States | |
| 13 | 88.49 miles (142.42 km) W | Cape Romanzof Air Force Station Cape Romanzof Long Range Radar Site (CZF) | Cape Romanzof, Alaska, United States | |
| 14 | 89.19 miles (143.53 km) SSW | Newtok Airport (WWT) | Newtok, Alaska, United States | |
| 15 | 89.22 miles (143.59 km) SSE | Atmautluak Airport (ATT) | Atmautluak, Alaska, United States | |
| Rank | Distance & Direction | Airport Name & IATA Code | Airport Location | Further Actions |
| 1 | 10,494.08 miles (16,888.54 km) S | Cape Town International Airport (CPT) | Cape Town, South Africa | |
| 2 | 10,482.44 miles (16,869.80 km) S | George Airport (GRJ) | George, South Africa | |
| 3 | 10,457.83 miles (16,830.21 km) SSW | Port Elizabeth International Airport (PLZ) | Port Elizabeth, South Africa | |
| 4 | 10,416.76 miles (16,764.12 km) SSW | Port Alfred Airport (AFD) | Port Alfred, South Africa | |
| 5 | 10,371.90 miles (16,691.92 km) SSW | East London Airport (ELS) | East London, South Africa | |
| 6 | 10,261.64 miles (16,514.46 km) SSW | Mthatha Airport (UTT) | Mthatha, South Africa | |
| 7 | 10,199.66 miles (16,414.71 km) S | Kleinsee Airport (KLZ) | Kleinzee, South Africa | |
| 8 | 10,195.75 miles (16,408.43 km) SSW | Margate Airport (MGH) | Margate, KwaZulu-Natal, South Africa | |
| 9 | 10,169.94 miles (16,366.89 km) S | Aggeneys Airport (AGZ) | Aggeneys, South Africa | |
| 10 | 10,169.94 miles (16,366.89 km) S | Wild Coast Sun Airport (MZF) | Mzamba, South Africa | |
| 11 | 10,157.43 miles (16,346.75 km) SSW | Mafeteng Airport (MFC) | Mafeteng, Lesotho | |
| 12 | 10,151.99 miles (16,338.00 km) SSW | Semonkong Airport (SOK) | Semonkong, Lesotho | |
| 13 | 10,149.37 miles (16,333.79 km) SSW | Lebakeng Airport (LEF) | Lebakeng, Lesotho | |
| 14 | 10,143.31 miles (16,324.03 km) SSW | Lesobeng Airport (LES) | Lesobeng, Lesotho | |
| 15 | 10,133.50 miles (16,308.25 km) SE | Teniente Rodolfo Marsh Airport (TNM) | Villa Las Estrellas, Antarctica | |