Large Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 96; Flight Crew Type 771
Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action
Airport; Environment - Non Weather Related
We were descending into Bozeman at night time. We were in IMC and cleared from LVM to KIDCO to begin the ILS 12 approach. We were cleared to 11000 after crossing LVM. Shortly before leveling at 11000 feet the radar altimeter began counting down from 2500 feet and the aural 2500 sounded. At about 11100 feet; 'terrain; terrain; pull up' sounded. The captain immediately executed the terrain avoidance maneuver.  After climbing to about 15000; we informed ATC and they cleared us to 10100 and cleared us for the approach. ATC did not seem to be concerned about our situation. There was no terrain displayed on the ND at any point during the descent and subsequent terrain warning. We executed the ILS 12 and landed with no further issues. There happened to be a deadheading pilot on the flight and he told us later that that was the third such situation he has heard of in the past year flying into BZN.
[Report narrative contained no additional information.]
During approach to BZN; aircrew experienced a GPWS terrain warning and executed the escape maneuver.