Nonstop flight route between Sidney, Montana, United States and Cahokia, Illinois (near St. Louis), United States:
Departure Airport:

Arrival Airport:

Distance from SDY to CPS:
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- About this route
- SDY Airport Information
- CPS Airport Information
- Facts about SDY
- Facts about CPS
- Map of Nearest Airports to SDY
- List of Nearest Airports to SDY
- Map of Furthest Airports from SDY
- List of Furthest Airports from SDY
- Map of Nearest Airports to CPS
- List of Nearest Airports to CPS
- Map of Furthest Airports from CPS
- List of Furthest Airports from CPS
About this route:
A direct, nonstop flight between Sidney-Richland Municipal Airport (SDY), Sidney, Montana, United States and St. Louis Downtown Airport (CPS), Cahokia, Illinois (near St. Louis), United States would travel a Great Circle distance of 946 miles (or 1,522 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 Sidney-Richland Municipal Airport and St. Louis Downtown Airport, the route shown on this map most likely still appears to be a straight line.
Departure Airport Information:
IATA / ICAO Codes: | SDY / KSDY |
Airport Name: | Sidney-Richland Municipal Airport |
Location: | Sidney, Montana, United States |
GPS Coordinates: | 47°42'24"N by 104°11'32"W |
Area Served: | Sidney, Montana |
Operator/Owner: | Sidney Richland Airport Authority |
Airport Type: | Public |
Elevation: | 1985 feet (605 meters) |
# of Runways: | 2 |
View all routes: | Routes from SDY |
More Information: | SDY Maps & Info |
Arrival Airport Information:
IATA / ICAO Codes: | CPS / KCPS |
Airport Name: | St. Louis Downtown Airport |
Location: | Cahokia, Illinois (near St. Louis), United States |
GPS Coordinates: | 38°34'14"N by 90°9'21"W |
Area Served: | Greater St. Louis |
Operator/Owner: | Bi-State Development Agency |
Airport Type: | Public |
Elevation: | 413 feet (126 meters) |
# of Runways: | 3 |
View all routes: | Routes from CPS |
More Information: | CPS Maps & Info |
Facts about Sidney-Richland Municipal Airport (SDY):
- Sidney-Richland Municipal Airport covers an area of 335 acres at an elevation of 1,985 feet above mean sea level.
- The closest airport to Sidney-Richland Municipal Airport (SDY) is Sloulin Field International Airport (ISN), which is located 41 miles (67 kilometers) NE of SDY.
- Sidney-Richland Municipal Airport (SDY) has 2 runways.
- The furthest airport from Sidney-Richland Municipal Airport (SDY) is Sir Gaëtan Duval Airport (RRG), which is located 10,383 miles (16,711 kilometers) away in Rodrigues Island, Mauritius.
Facts about St. Louis Downtown Airport (CPS):
- The airport opened in 1929 as Curtiss-Steinberg Airport.
- Because of St. Louis Downtown Airport's relatively low elevation of 413 feet, planes can take off or land at St. Louis Downtown 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 furthest airport from St. Louis Downtown Airport (CPS) is Margaret River Airport (MGV), which is located 10,998 miles (17,700 kilometers) away in Margaret River, Western Australia, Australia.
- The closest airport to St. Louis Downtown Airport (CPS) is Lambert–St. Louis International Airport (STL), which is located only 16 miles (27 kilometers) NW of CPS.
- St. Louis Downtown Airport (CPS) has 3 runways.
- Taken over by the United States Army Air Forces on 1 August 1939 as a basic pilot training airfield.