DRG ARRIVAL, THE PLT ENTERED THE TRAFFIC PATTERN TO LAND ON RWY 3. HE STATED THAT ON FINAL APCH, THE ACFT DESCENDED BELOW THE THRESHOLD OF THE RWY. ALSO, HE RPRTD HE RAISED THE NOSE & ADDED POWER, BUT THE MAIN LANDING GEAR STRUCK A BERM AT THE APCH END OF THE RWY. THE LANDING GEAR SEPARATED FROM THE ACFT & THE ACFT SLID TO A STOP ON THE LEFT SIDE OF THE RWY. THE PLT RPRTD THE WIND WAS FROM THE EAST AT 10, GUSTING 20 KTS.