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

Arrival Airport:

Distance from CPS to SDY:
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- About this route
- CPS Airport Information
- SDY Airport Information
- Facts about CPS
- Facts about 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
- Map of Nearest Airports to SDY
- List of Nearest Airports to SDY
- Map of Furthest Airports from SDY
- List of Furthest Airports from SDY
About this route:
A direct, nonstop flight between St. Louis Downtown Airport (CPS), Cahokia, Illinois (near St. Louis), United States and Sidney-Richland Municipal Airport (SDY), Sidney, Montana, 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 St. Louis Downtown Airport and Sidney-Richland Municipal Airport, the route shown on this map most likely still appears to be a straight line.
Departure 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 |
Arrival 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 |
Facts about St. Louis Downtown Airport (CPS):
- The airport opened in 1929 as Curtiss-Steinberg Airport.
- 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.
- 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.
Facts about Sidney-Richland Municipal Airport (SDY):
- 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.
- Sidney-Richland Municipal Airport (SDY) has 2 runways.
- 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 covers an area of 335 acres at an elevation of 1,985 feet above mean sea level.