Whetstone International Airport

General Aviation Airport Fact Sheet 
Whetstone International Airport (KH28) 
4071 Chalk Butte Road, Cut Bank, MT 59427
Regular Office Hours 
7 days per week, 0930-1630 
Mountain Time (MT) 
 
 
  
 
 
 
 
Contact Information 
(406) 336-2130   CBP Del Bonita, MT Port of Entry
KH28_GAP@cbp.dhs.gov
Hours of Service for Entrance 
and Clearance 
Inspection services for the entrance/
arrival of aircraft at Whetstone 
International Airport are available 
during regular office hours in 
accordance with the port's permission 
to land procedures.  
Commercial aircraft operators 
departing the U.S. must obtain an 
outbound clearance by contacting CBP 
directly. 
Permission to Land Procedures 
Pilots must secure permission to land by contacting CBP 
at least two hours prior to departure from the foreign port 
or place.
Permission to land is granted with a tolerance of (+/-) 30 
minutes. If your ETA deviates outside these parameters, 
previously granted permission(s) are invalid and you 
must contact CBP to re-secure permission to land.  
Inspection Process 
• Aircraft should park at the west end of the runway.
• Crew and passengers must wait in the area of the aircraft until a CBP Officer arrives.
• Once the aircraft is inspected travelers will be processed inside the Port of Entry.
Special Procedures/Miscellaneous 
• Regular  office hours:
o Current Hours: M-F 0900-1700
• The Frank Whetstone International Airport is a grass landing strip that can be used by aircraft to
enter the U.S.
• Permission to land must be obtained from a CBP officer at least two hours prior to departure from
the foreign port or place
• Permission to land will only be granted during business hours.
NOTE: For further detailed information regarding national GA processing standards and procedures, 
please refer to the CBP Private Aircraft Arrival Information Document or contact GAsupport@cbp.dhs.gov 
October 22, 2025 Publication Number KH28-1025 
Whetstone International Airport