Big Blackfoot Railroad

By editor

Greenough, Missoula County, Montana, April 2026

The Shay locomotive is not a beautiful machine. It is, in fact, one of the more peculiar-looking devices ever to run on rails. Where a standard locomotive has its pistons driving the wheels directly, the Shay has its cylinders mounted vertically on the right side of the boiler, driving a horizontal shaft that runs the length of the engine and connects, through a series of bevel gears, to each axle. The result is a machine that looks as though it was assembled by a committee that could not agree on anything except that the job had to get done. It wobbles. It clanks. It moves at a speed that a determined man on foot could match on a level grade. And it will climb a mountain that would stop any other locomotive cold.

The Anaconda Company knew exactly what it was doing when it ordered two Shay engines from the Lima Locomotive Works in Lima, Ohio, in the early 1900s. The company had been running the Big Blackfoot Milling Company at Bonner since the 1880s, and by 1900 the nearby timber was gone. The mill had eaten it. Thousands of board feet per day, year after year, until the hills around Bonner were stripped to the soil and the logs had to come from somewhere farther up the river. The company had been floating logs down the Blackfoot from camps at Potomac, using more than 300 horses in the winter to drag them to the water. That system had its limits. The river was not always cooperative, and horses, unlike locomotives, require feed and veterinary care and occasionally die.

The solution was a railroad. Not a grand transcontinental affair with Pullman cars and dining service, but a working railroad built for a single purpose: to drag timber out of the upper Blackfoot Valley and get it to the mill. The company hauled everything needed for construction, including the disassembled Shay engines, in wagons and sleighs eleven miles up the Blackfoot to a place called McNamara's Landing. From there, the crews built the Big Blackfoot Railroad through Potomac to Greenough, roughly fourteen miles of track through country that had never seen a rail. The line was completed by 1904.

The Shay engines were the right tool for this particular piece of work. The Blackfoot Valley is not flat. The grades that the logging branches had to climb to reach the timber would have stalled a conventional locomotive before it got started. The Shay's geared drive gave it a pulling force that was nearly independent of wheel slip, which meant it could haul a loaded log car up a grade that would have left a standard engine spinning its wheels and going nowhere. The trade-off was speed, and on a logging railroad, speed was not the point. Getting the logs out was the point.

The line had a feature that distinguished it from most railroads: its branch lines were temporary. When a section of forest was cleared, the branch serving it was pulled up and relaid somewhere else. The main line from McNamara's Landing to Greenough was permanent enough, but the fingers reaching into the timber were moved as the timber moved, which is to say as the timber disappeared. The Anaconda Company was not in the business of preserving forests. It was in the business of converting forests into lumber, and the Big Blackfoot Railroad was the instrument of that conversion.

When the logs reached McNamara's Landing, they were dumped into the river and floated the remaining distance to Bonner. The mill at Bonner was one of the largest in the Pacific Northwest, capable of processing enormous volumes of timber, and it required a continuous supply to keep running. The railroad provided that supply with a regularity that the old floating system could not match.

By 1913, the Anaconda Company had decided to sell the Big Blackfoot Railway to the Milwaukee Road, which was building its Pacific Extension through the Blackfoot Valley at the time. The Milwaukee extended the line to McNamara's Landing and eventually all the way into Bonner from Potomac, crossing the Clark Fork on a bridge just east of the Milltown Dam that the locals called the Duck Bridge. Lumber from the Bonner mill would go into Missoula and then be attached to Milwaukee trains heading east or west.

The Milwaukee Road's Pacific Extension was itself one of the great engineering achievements of the early twentieth century, a line that crossed the Rockies and the Cascades using electric locomotives on the mountain grades. The Big Blackfoot branch was a modest appendage to that grand enterprise, a working railroad serving a working mill, with none of the romance that attached to the main line. But it was the Big Blackfoot Railroad, not the Milwaukee's electrified mountain grades, that actually got the timber out of the upper Blackfoot Valley and kept the Bonner mill running through the first decades of the century.

One of the two original Shay engines survives. It sits today at the Historical Museum at Fort Missoula, retired from service but not yet reduced to scrap. It is still an ugly machine. The vertical cylinders are still mounted on the right side of the boiler, the bevel gears are still visible along the drive shaft, and the whole assembly still looks like something that should not work but does. The Blackfoot Valley is quieter now than it was when the Shay was running. The mill at Bonner is gone. The Duck Bridge is gone. The Milwaukee Road abandoned its Pacific Extension in 1980, and the tracks were pulled up. But the Shay sits in Fort Missoula and does not apologize for what it was built to do.

The Philipsburg Mail reported in the summer of 1904 that the new railroad had "opened the upper Blackfoot to systematic lumbering operations on a scale not previously attempted in this part of the territory." The editor was right about the scale. He did not mention, because it was not yet apparent, that systematic lumbering operations on that scale would eventually exhaust the upper Blackfoot just as they had exhausted the lower Blackfoot, and that the railroad would then have nothing left to haul.

See also

• Big Blackfoot Railroad at Greenough, Missoula County (Montana Department of Transportation, erected 2012)
• Savenac Nursery Historic District at Haugan, Mineral County -- the federal nursery that replanted the forests after the 1910 fires
• Ghost Town Byway at Greenough, Missoula County -- the Garnet Range gold mines that drove early settlement of this corridor