Nonstop flight route between Diomede, Alaska, United States and Sidney, Montana, United States:
Departure Airport:

Arrival Airport:

Distance from DIO to SDY:
Share this route:
Jump to:
- About this route
- DIO Airport Information
- SDY Airport Information
- Facts about DIO
- Facts about SDY
- Map of Nearest Airports to DIO
- List of Nearest Airports to DIO
- Map of Furthest Airports from DIO
- List of Furthest Airports from DIO
- 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 Diomede Heliport (FAA: DM2) (DIO), Diomede, Alaska, United States and Sidney-Richland Municipal Airport (SDY), Sidney, Montana, United States would travel a Great Circle distance of 2,598 miles (or 4,181 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 large distance between Diomede Heliport (FAA: DM2) and Sidney-Richland Municipal Airport, the route shown on this map most likely appears curved because of this reason.
Try it at home! Get a globe and tightly lay a string between Diomede Heliport (FAA: DM2) and Sidney-Richland Municipal Airport. You'll see that it will travel the same route of the red line on this map!
Departure Airport Information:
IATA / ICAO Codes: | DIO / |
Airport Name: | Diomede Heliport (FAA: DM2) |
Location: | Diomede, Alaska, United States |
GPS Coordinates: | 65°45'29"N by 168°57'6"W |
Elevation: | 0 feet (0 meters) |
View all routes: | Routes from DIO |
More Information: | DIO 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 Diomede Heliport (FAA: DM2) (DIO):
- The Little Diomede island is composed of Cretaceous age granite or quartz monzonite.
- The closest airport to Diomede Heliport (FAA: DM2) (DIO) is Wales Airport (WAA), which is located 26 miles (42 kilometers) ESE of DIO.
- Because of Diomede Heliport (FAA: DM2)'s relatively low elevation of 0 feet, planes can take off or land at Diomede Heliport (FAA: DM2) 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.
- At the beginning of the Cold War in the late 1940s Big Diomede became a Russian military base and all its native residents were removed to mainland Russia.
- The island's only school, and likely the most isolated school in the United States, the Diomede School has grades from Pre-K through 12 and approximately 40 students and 5 teachers.
- The first square building in the island was a small Catholic church, which was planned by Father Bellarmine Lafortune in 1935 and built by Father Thomas Cunningham during his residency in the island between 1936 and 1947.
- The furthest airport from Diomede Heliport (FAA: DM2) (DIO) is Teniente Rodolfo Marsh Airport (TNM), which is located 10,411 miles (16,755 kilometers) away in Villa Las Estrellas, Antarctica.
Facts about Sidney-Richland Municipal Airport (SDY):
- As per the Federal Aviation Administration, this airport had 2,031 passenger boardings in calendar year 2008, 2,766 in 2009, and 3,659 in 2010.
- 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.
- 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.