Nonstop flight route between Portsmouth, Ohio, United States and Alton, Illinois, United States:
Departure Airport:

Arrival Airport:

Distance from PMH to ALN:
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- About this route
- PMH Airport Information
- ALN Airport Information
- Facts about PMH
- Facts about ALN
- Map of Nearest Airports to PMH
- List of Nearest Airports to PMH
- Map of Furthest Airports from PMH
- List of Furthest Airports from PMH
- Map of Nearest Airports to ALN
- List of Nearest Airports to ALN
- Map of Furthest Airports from ALN
- List of Furthest Airports from ALN
About this route:
A direct, nonstop flight between Greater Portsmouth Regional Airport (PMH), Portsmouth, Ohio, United States and St. Louis Regional Airport (ALN), Alton, Illinois, United States would travel a Great Circle distance of 387 miles (or 623 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 Greater Portsmouth Regional Airport and St. Louis Regional Airport, the route shown on this map most likely still appears to be a straight line.
Departure Airport Information:
IATA / ICAO Codes: | PMH / KPMH |
Airport Name: | Greater Portsmouth Regional Airport |
Location: | Portsmouth, Ohio, United States |
GPS Coordinates: | 38°50'26"N by 82°50'49"W |
Area Served: | Portsmouth, Ohio |
Operator/Owner: | Scioto County Airport Authority |
Airport Type: | Public |
Elevation: | 663 feet (202 meters) |
# of Runways: | 1 |
View all routes: | Routes from PMH |
More Information: | PMH Maps & Info |
Arrival Airport Information:
IATA / ICAO Codes: | ALN / KALN |
Airport Name: | St. Louis Regional Airport |
Location: | Alton, Illinois, United States |
GPS Coordinates: | 38°53'25"N by 90°2'45"W |
Area Served: | Alton, Illinois |
Operator/Owner: | St. Louis Regional |
Airport Type: | Public |
Elevation: | 544 feet (166 meters) |
# of Runways: | 2 |
View all routes: | Routes from ALN |
More Information: | ALN Maps & Info |
Facts about Greater Portsmouth Regional Airport (PMH):
- Greater Portsmouth Regional Airport (PMH) currently has only 1 runway.
- The furthest airport from Greater Portsmouth Regional Airport (PMH) is Margaret River Airport (MGV), which is located 11,385 miles (18,322 kilometers) away in Margaret River, Western Australia, Australia.
- The airport was constructed in the 1957 to replace another airport located in West Portsmouth, Ohio which was situated near the Ohio River.
- The closest airport to Greater Portsmouth Regional Airport (PMH) is Lawrence County Airpark (HTW), which is located 35 miles (56 kilometers) SSE of PMH.
- Because of Greater Portsmouth Regional Airport's relatively low elevation of 663 feet, planes can take off or land at Greater Portsmouth Regional 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.
- Greater Portsmouth Regional Airport covers an area of 246 acres at an elevation of 663 feet above mean sea level.
Facts about St. Louis Regional Airport (ALN):
- Its operations are paid for by an airport taxation district created in 1946, which collects taxes from property owners in the Madison County townships of Alton, Wood River, Foster and Fort Russell.
- St. Louis Regional Airport (ALN) has 2 runways.
- The furthest airport from St. Louis Regional Airport (ALN) is Margaret River Airport (MGV), which is located 11,002 miles (17,706 kilometers) away in Margaret River, Western Australia, Australia.
- Today a fair amount of air traffic and the Direct TV blimp comes for Cardinals playoffs, as Lambert's airport cannot take the blimp.
- The closest airport to St. Louis Regional Airport (ALN) is Lambert–St. Louis International Airport (STL), which is located only 20 miles (32 kilometers) WSW of ALN.
- Because of St. Louis Regional Airport's relatively low elevation of 544 feet, planes can take off or land at St. Louis Regional 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.