Narrative:

Tower controller complacent. Kept aircraft X headed toward geg (field lights were off) until turn to downwind was too close abeam the field. Visual approach with rising terrain to the east, caused actuation of terrain avoidance.

Google
 

Original NASA ASRS Text

Title: AN A310 CREW, ON VISUAL APCH TO GEG, RECEIVED A GPWS 'TOO LOW TERRAIN' WARNING.

Narrative: TWR CTLR COMPLACENT. KEPT ACFT X HEADED TOWARD GEG (FIELD LIGHTS WERE OFF) UNTIL TURN TO DOWNWIND WAS TOO CLOSE ABEAM THE FIELD. VISUAL APCH WITH RISING TERRAIN TO THE E, CAUSED ACTUATION OF TERRAIN AVOIDANCE.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.