For 20 years, BNSF Railway has maintained a unique avalanche program to keep its main line to the Pacific Northwest open.
It only took a few months for the Great Northern Railway to realize that railroading on Montana’s Marias Pass would not be for the faint of heart—especially in winter.
While the GN faced many obstacles in the 1,000 miles from St. Paul, Minn., to the foot of the Rocky Mountains, none were quite like what it encountered on its newly built main line along the southern edge of what would eventually become Glacier National Park. On Feb. 9, 1893, just months after regular service began over Marias Pass, a local newspaper reported that “the work of clearing the Great Northern track of snow is being carried on vigorously, but the mountain division is proving a harder piece of road than any on the system.”
More than a century later, that challenge persists for GN’s successor, BNSF. And while deep snow and frigid temperatures are a constant difficulty for railroaders in winter here, the most destructive foes are the snow slides that occur along a stretch of main line on the Hi Line Subdivision known as “Avalanche Alley.” But for the past 20 years, BNSF has maintained a unique avalanche forecasting program that keeps railroaders and passengers safe and traffic moving through an unforgiving landscape.
Unforgiving Territory
Although Marias Pass is among the lowest crossings of the Continental Divide at 5,213 feet above sea level, it still receives an average of 250 inches of snow annually. To handle that, BNSF bases a fleet of snow-fighting equipment at Essex, Mont.. During the winter, the railroad employs flangers (called “flyers” by local railroaders) and spreaders to keep the main line open, as well as maintenance-of way-equipment outfitted with plows.
Essex has been ground zero for the fight against Old Man Winter for more than a century. Although, in the late 19th and early 20th century, it could also be a deadly one, especially when avalanches came careening down the side of John F. Stevens Canyon (The canyon was named for the GN engineer who first mapped the route over Marias Pass in 1889). By some estimates, more than a dozen railroaders were killed in avalanches on Marias Pass between the 1890s and 1930s. The deadliest avalanche anywhere in North America occurred further west on the GN in the Cascade Mountains, when a slide struck two trains parked near Wellington, Wash., killing 96 people in 1910. The tragedy resulted in the construction of the 7.8-mile-long Cascade Tunnel, which allowed the main line to avoid slide-prone terrain.
To protect the right-of-way on the west slope of Marias Pass, the GN built a dozen snowsheds between 1912 and 1930. Most of the sheds were constructed along a four-mile stretch of track east of Essex, where the railroad and U.S. Highway 2 are sandwiched between Glacier National Park and the Flathead National Forest. Today, ten of those sheds remain, protecting the double-track main line from 12 major avalanche paths and 26 different slide-starting zones.
While the snow sheds cover the main line at some of its most vulnerable points, the structures are not always a surefire way to protect the tracks, especially if a slide is big enough to take out the shed. That was the case in February 1956, when a slide destroyed the end of a snow shed in a blizzard. Shortly after, an eastbound train slammed into a wall of snow, breaking the window of the lead unit and pinning the locomotive engineer inside. Thankfully, other crew members were able to dig him out and he escaped uninjured.
On Jan. 28, 2004, two separate avalanches struck an eastbound BNSF grain train east of Essex, derailing 15 cars. Later, another avalanche came down the path of the first slide just minutes after employees had been inspecting the train at that location. After that incident, BNSF contacted avalanche forecaster and consultant David Hamre, the head of the Alaska Railroad’s avalanche mitigation program dating back to the 1980s. Hamre spent a few days creating a revised avalanche map for John F. Stevens Canyon and recommended that BNSF start its own avalanche forecasting program. The BNSF avalanche team was established in the winter of 2005 under the leadership of forecaster Ted Steiner.
Forecasting in Avalanche Alley
BNSF is not the only railroad in the West with an avalanche program. The Alaska Railroad has one to keep an eye on the slopes along the rail line between Anchorage and Seward, and Union Pacific maintains one on Donner Pass in California. In both instances, the railroads will often conduct avalanche mitigation to ensure slides come down in a controlled manner when it is safe to do so. But BNSF’s program is unique because the rail line over Marias Pass is right next to Glacier National Park and most of the avalanche starting zones and paths are within the park. Because of that, the railroad can only conduct avalanche mitigation when extreme conditions warrant, and public safety is at risk. The railroad must get a special-use permit from the National Park Service before it conducts any mitigation.
Those restrictions mean knowledge is the primary weapon in BNSF’s battle against the elements. One person who provides that knowledge is Adam Clark, forecaster and avalanche program manager. From November to April, Clark and Steiner (who is now the assistant program manager) study weather and snow conditions across the forecast area. BNSF owns and maintains five weather stations in John F. Stevens Canyon and jointly maintains a sixth in partnership with the Flathead Avalanche Center.
Once or twice a week, Clark or Steiner will inspect avalanche conditions above the rail line firsthand, using skis or snowshoes to reach remote locations. One of the best ways to do that is to dig snow pits and perform stability tests on the snow. Digging into the snow lets the forecasters see the many different layers of snow and ice that have formed over the course of the winter. By performing a compression test, usually by placing a shovel at the top of the snow and then applying pressure to it, they can see where the snow falls and, thus, where the weakest layer is. Much like a birthday cake, snow falls in layers and some layers are stronger than others. Strength often depends on water content or what the temperature was when it fell. Clark said he is often looking at snowpack trends that develop throughout the season and that information is used to help craft his forecasts.
Observations from the field and the information from the weather stations help Clark put together an avalanche forecast, which lets the railroad know if snow conditions are stable or if the risk of an avalanche is increasing. When dangerous avalanche conditions are present, Clark or Steiner are usually in Essex around the clock. “The reality is there is no normal day, and I think that’s what I love about the work so much,” Clark said.
Clark’s avalanche forecasts are key in helping the railroad determine if the threat of a slide is imminent and whether the rail line should be shut down. Lena Kent, BNSF’s general director of public affairs, said line closures are rare but that they do occur. One of the most recent closures happened in 2021 when a slide blocked both main line tracks. After clearing the slide, the railroad reopened for a few more days until the avalanche danger increased again, at which point the railroad got permission from the National Park Service to conduct mitigation.
In the past, Glacier Park has allowed the railroad to use hand charges that can be tossed by a human or dropped from a helicopter, or an “Avalauncher,” which can shoot explosives from a distance. The most unusual tool for mitigation is a “DaisyBell,” which is a hydrogen combustion cylinder suspended from a helicopter that fires pressure waves at the slope to trigger slides.
Besides producing forecasts and on rare occasions leading mitigation efforts, BNSF’s avalanche team also provides avalanche safety training for railroad employees who work in the area, particularly maintenance-of-way crews. Those courses include classroom time where railroaders learn basic avalanche rescue skills, before moving into the field where they practice various rescue scenarios as well as familiarizing themselves with how to use avalanche transceivers. An avalanche transceiver is a radio beacon worn by people working or recreating in the backcountry that can help rescuers find them if they are buried in a slide.
While the avalanche program’s focus is on keeping railroaders and passengers traversing Marias Pass safely, it also benefits the wider community. The BNSF team shares its field observations with the Flathead Avalanche Center, which provides avalanche forecasts for skiers, snowboarders, snowmobilers and others recreating in northwest Montana. The railroad also maintains its own website, avalanchealley.com, where avalanche, snowpack and weather observations are shared with the public and researchers. Data from BNSF’s five weather stations in John F. Stevens Canyon is also shared publicly and used by the National Weather Service, as well as wildland firefighting teams in the summer.
One-hundred and thirty-three years after trains first began traversing Montana’s Marias Pass, Mother Nature can still set the agenda for railroaders working here during cold and harsh winters. But for the past 20 years, that endeavor has been safer thanks to BNSF’s avalanche program.
