That booming sound you hear near the southern boundary of Glacier National Park could be from avalanche control work above the tracks of the Burlington Northern Santa Fe Railway tracks.

The railroad sought the special permission due to the heavy snow year they're having in northern Montana. The special-use permit allows the railroad to conduct emergency avalanche hazard mitigation activities in an area along the Glacier's southern boundary, park officials said Thursday.

Avalanche mitigation activities will take place in the John F. Stevens Canyon area along the U.S. Highway 2 Corridor. Recent avalanche activity in this area prompted the railroad to request the permit due to the safety of BNSF Railway employees and passengers aboard trains.

“We are working with BNSF Railway to create safe conditions for their employees and passengers along the southern boundary of the park, and will continue to work with them to find long-term solutions," said Glacier Superintendent Jeff Mow.  

The permit only allows the use of hand charger devices, an 'avalauncher,' or explosive charges delivered by a helicopter, and only during daylight hours, a park release said.

The planned mitigation activity is the use of a Daisy Bell. This avalanche mitigation technique uses a cylinder suspended from a helicopter that can be accurately positioned above the snowpack. It uses a small, controlled pressure wave from the sudden combustion of hydrogen to trigger the snow.

The railroad was expected to begin the control activities Thursday. For updated information on avalanche hazard mitigation activities and related activities along the southern border of Glacier National Park, please contact the railroad at 406-589-6891 or at [email protected].

You can also visit the Montana Department of Transportation website for road closures. 

“This year's highly variable weather conditions are resulting in an unstable snowpack and several uncommon events across Montana," Superintendent Mow said.

It is anticipated that recent weather has contributed to snow slides throughout the park, including one near the Goat Lick area south of the park. Blocked drainages are of concern, and the park plans to begin some monitoring throughout the park to identify these situations. If anyone has any information on any snow slides or related activities within the park, you're asked to park headquarters at 406-888-7800.

Some years ago the railroad had sought permission to do avalanche control along that corridor on a regular basis. At the time, railway officials approached Glacier officials about the possibility of lobbing 105 mm explosives at key avalanche chutes in the area of Scalplock, Running Rabbit, Snowslip and Mount Shields mountains in John Stevens Canyon. The request came in the wake of a 2004 avalanche that caused a derailment along the boundary.

Park Service officials rejected that request, and suggested that BNSF construct additional snowsheds and to add on to existing ones in high-risk avalanche paths.