A power line contractor came by the maintenance planner's office and told him he noticed a gas pipeline leak near the auxillary stockpile area. MSHA was immediately called and the haul road near the leak was blocked to thru traffic. The pipeline was closed in and the pressure bled down. The haul road was re-opened at approx. 1:30 pm. Repairs completed at 6:00 pm 9/28/07.