MOORHEAD — The Northern Pacific Railway had a big problem. Solving it would require cutting down thousands of trees and dumping thousands of cars of earth. It also would cost 20 men their lives.
The railroad was rushing in 1871-72 to complete its line linking Duluth and the Great Lakes to Seattle and the Pacific Northwest.
The engineers who designed the route knew that the grade as it exited the Red River Valley at the site of the ancient glacial Lake Agassiz beach ridge was too steep as originally built.
“They were in a hurry to get to the West Coast,” said Mark Peihl, archivist at the Historical and Cultural Society of Clay County. “They knew they’d have to do something about it later.”
The grade east of Glyndon, Minn., was so steep that the Northern Pacific stationed a special engine car in Fargo that was used to push trains up the 1½% grade, a rise of 1½ feet every 100 feet.
“That was significant,” Peihl said. “That was pretty steep.”
Even with a push, the steep grade slowed down rail traffic. By 1906, the abrupt rise on the edge of the valley was the cause of the biggest bottleneck of rail traffic in the eastern United States. The bottleneck delayed shipments of vital cargo, including timber from the Pacific Northwest, cattle from Montana and wheat from the Dakotas.
“By 1906, they had to do something about it,” Peihl said.
That something was called the Stockwood Fill, an enormous earthen berm with a gradual grade to ease rail traffic over the glacial beach ridge between Glyndon and Hawley.
The center of the Fill was 4¾ miles long and involved erecting a massive wooden trestle that would serve as the structure’s skeleton.
“It looked like a big wooden bridge running across the prairie,” said Peihl, who is giving a talk on the Stockwood Fill at 7 p.m. Tuesday, March 16. It will be webcast on Zoom and Facebook live.
For about a mile on either side of the trestle, workers built earthen ramps. Tens of thousands of fir trees were cut down in Washington state for the wooden structure. Once the frame was complete, it was topped with a railroad, from which cars dropped thousands of loads of dirt.
The 7.3-mile Stockwood Fill is visible today south of U.S. Highway 10 between Glyndon and Hawley, appearing as an elongated earthen ridge.
“That’s what they run those trains on today,” Peihl said. “All that wood is buried there still.”
The elevated track has three openings, one for the entrance to Buffalo River State Park — where the structural timbers are still visible — and another to allow Highway 9 to run beneath the tracks and a third to allow the Tally Ho Road to pass under.
The project took three years, 1906 to 1909, to complete. That was time enough to consume more than 2 million board feet of lumber and to dump more than 5 million cubic tons of dirt and gravel into the Fill.
But the geology of the Red River Valley had unpleasant surprises for the Northern Pacific Railway.
The spongy subsoils collapsed under the earthen load, and the railroad found itself in a futile cycle of dumping more dirt to try to level the dip, only to see the added soil sink once again as the subsoils gave way, once again.
Or, as Peihl said: “The railroad had a hell of a time building the thing. It sank and sank and sank.”
The long-running construction project was chronicled in newspapers and drew gawkers who wanted to see the spectacle for themselves, a dramatic alteration to the tabletop flat landscape.
“It was a pretty spectacular project that everyone was watching,” Peihl said.
The engineer in charge of construction, Samuel A. McCoy, stubbornly kept trying to fill the slump, delaying the project and adding $700,000 to the $2.1 million budgeted cost — obstinacy that ultimately cost him his position.
“He seems to have had quite an ego about him,” Peihl said. “Quite stubborn.”
McCoy’s replacement, F. L. Birdsall, was less obsessive than his predecessor. Once crews kept dropping in more dirt the slumping stopped. The Northern Pacific conceded defeat.
“He seems to have been more levelheaded,” Peihl said of Birdsall. “Really, it was time to throw in the towel.”
The Stockwood Fill proved costly in human terms. Twenty men died, most from building the trestle, most of those from falling debris. Many others suffered broken bones or lost appendages, Peihl said.
“Lots and lots of broken arms and legs and lost hands,” Peihl said. The Northern Pacific had its own hospital in Brainerd, where workers went to be patched up.
The railroad’s goal when it started the Stockwood Fill was to reduce the grade to 3/10 of 1%, but ended up settling with a grade of 7/10 of 1% — still much more gradual than the original 1½%.
But the bottleneck was solved, thanks to the troublesome Stockwood Fill, and freight moving on the transcontinental rail line was able to easily surmount the beach ridge of the long-vanished glacial lake.
If you go
What: Online talk about construction of the Stockwood Fill presented by the Historical and Cultural Society of Clay County
When: 7 p.m. Tuesday, March 16
Details: Register and find links to Zoom and Facebook live webcasts at https://www.hcscconline.org/events.html