Need help booking?
Unpublished phone-only deals available
FSI to ISN: distance & flight time
Fort Sill (Henry Post Army Air Field (Fort Sill)) → Williston (Sloulin Field International Airport)
973 mi
1,565 km · 845 nm
2h 35m
estimated nonstop flight time
Same time
time difference · heading north
See live FSI→ISN fares Phone-only fares on this route — call free
Flight time details
973 miles nonstop takes roughly 2h 35m gate to gate, flying north. Add 45–90 minutes per connection if there's no nonstop service. Both airports share the same local time, so schedules read exactly as flown.
The two airports
- FSI — Henry Post Army Air Field (Fort Sill) · Fort Sill, United States
- ISN — Sloulin Field International Airport · Williston, United States
Distances are great-circle ("as the crow flies") — the same basis airlines use for frequent-flyer miles.
Alternate airports can cut this fare
Flying from or into a nearby airport is the #1 trick our agents use to beat online prices. Call and we'll compare every combination on one call.
Near FSI
- LAW · Lawton Fort Sill Regional Airport6 mi away
- DUC · Halliburton Field28 mi away
- HBR · Hobart Regional Airport44 mi away
- SPS · Sheppard Air Force Base-Wichita Falls Municipal Airport46 mi away
Near ISN
- SDY · Sidney - Richland Regional Airport41 mi away
- YEN · Estevan Airport78 mi away
- OLF · L M Clayton Airport89 mi away
- GDV · Dawson Community Airport90 mi away
Frequently asked questions
How far is FSI from ISN?
The flight distance from Fort Sill (FSI) to Williston (ISN) is 973 miles (1,565 km, 845 nautical miles), measured along the great-circle route airlines actually fly.
How long is the flight from FSI to ISN?
A nonstop flight takes about 2h 35m gate to gate. Actual time varies with winds, routing and season — eastbound transatlantic flights, for example, are usually faster than the return.
What is the cheapest way to fly from FSI to ISN?
Compare live fares online, then call CheapoTrav — our agents have unpublished consolidator fares on FSI–ISN that never appear on search engines, with no booking fees.