History of the Rotary Snowplow on Colorado's Mountain Highways

Keeping Colorado’s mountain passes open for the winter is not easy. Many of the passes that are now open year-round used to close for the winter. As automobiles became more popular in the early 1900s, and the highways become more important for commerce, keeping the mountain passes open turned into a priority. Plowing equipment needed to be invented to tackle the task of keeping these roads open year-round in Colorado. The high mountain passes in Colorado presented the toughest challenges of all.

Berthoud Pass rotary snowplow historical photo with Snogo snowplow in year 1932
A Snogo rotary snowplow on Berthoud Pass, 1932

Colorado's Own Rotary Snowplow for the Railroads

The Canadians are credited with the first rotary snowplow patent and the first working rotary plow. However, they were not the only game in town. 

A miner named John Q. Day from Bells Camp, CO tried to patent a rotary snowplow design, which he later sold for $27k. However, the dollar amount of the sale can be disputed.1 2

From the Railroads Tracks to the Highways

Rotary snowplows had proven to be successful in keeping the railway lines into the mountains open, and taking the rotary snowplow concept onto the highways enabled some of the snowiest mountain passes to stay open all winter.

The rotary snowplows that were used by railroads were enormous and they were not cheap either. Union Pacific bought a Cooke rotary snowplow for $15,000 in 1889.3 The largest rotary snowplow in the Colorado mountains at the time was owned by the Midland Railroad Company, and that plow cost them $20k in the year 1888.4

Something smaller needed to be built for use on the highways.

rotary snowplow on railroad on Hagerman Pass Colorado by William H. Jackson
Colorado Midland RR on Hagerman Pass, 1899, William H. Jackson. Library of Congress.

CO Highway Commission Builds a Custom Rotary Snowplow for the Highways

At least two experimental rotary snowplows were built in Colorado during the mid-1920s. One was built by the CO State Highway Department, and the other was build by a lumberjack named Kid Hoover who lived near Red Cliff.

April 26, 1922 – The Craig Empire reports that the State Highway Commission had built a rotary snowplow to be used on highways. It was smaller than the rotary plows that were used for railroads, but based on the same design. The plan was to test the plow on Berthoud Pass that spring, and use it on Rabbit Ears Pass and other passes if it worked well.  The effort was led by Major Blauvelt of the highway department, and he is also given credit for the design.5

The plow’s fan was powered by a Continental motor, while the plow was pushed by 10 ton Holt caterpillar-style tractor. The rotating fan had a diameter of approx. 10 feet and could clear drifts that were 5 feet deep. It could throw snow 75 feet in the air, and It was built from scrapped truck parts and war materials that were furnished by the US Gov’t.6

The Kid Hoover Custom Rotary Snowplow

1924 – Kid Hoover, an ore hauler, timber and lumberjack man, invented his own version of the rotary snowplow. It could pick up snow to within 3 inches of the ground along a path that was 2 car lengths wide. The Holy Cross Trail newspaper reported about his new rotary plow and intent to use it to keep Tennessee Pass open in the winter of 1924-’35.1 However, the pass would fail to stay open during that season.

Meanwhile, off in Wisconsin...

Colorado was not the only place where people were developing adaptations of the rotary snowplows that were used by the railroads. Companies building early rotary snowplows here included Winther and the Milwaukee Snow Conveyor Company. The example shown below had two rotating elements. There was a circular rotating set of blades as well as a horizontal conveyor, both intended to help move snow off to the side.

historical experimental rotary snowplow made by the milwaukee snow conveyor company
Milwaukee Snow Conveyor Company, 1923

Testing Colorado's First Rotary Snowplow

The State’s plow still had not been tested by September of 1922, but they were planning to use the plow to keep Berthoud Pass open throughout the winter.7

The first tests were actually done in Douglas County, on the highway between Palmer Lake and Greenland, CO (this is on the edge of the Rocky Mountain foothills). The tests were done by March, and it was reported that the plow worked well, but improvements were planned in addition to more testing.6

Off to War at Berthoud Pass

1924 – The first reports of a rotary snowplow being deployed to Berthoud Pass came in the spring of 1924 on May 14th. A rotary plow had been sent on the previous day to clear snow.8

The pass was opened the week of June 11th, 1924, a record-setting early opening for this pass. This was the first time that a rotary snowplow was used to open a state highway in Colorado.9

Arrival of the Snogo

If you needed to run a serious mountain snow removal operation in the early to mid-1900s, Snogo was your go-to company. These rotary snowplows could be found throughout the country’s toughest passes from Colorado to California and the northwest. The Snogo design no longer used a large vertical fan like the railroad snowplows. Instead, these rotary snowplows now utilized an auger-style plow that looked a lot like a modern-day snowblower. 

The image below shows an early Snogo clearing snow at the top of Berthoud Pass. A few sets of skis and poles can be seen planted in the snow in the foreground because Berthoud Pass had become a popular spot for skiing in the first half of the 20th century.

Snogo rotary snow plow on berthoud pass circa 1940
Berthoud Pass, c. 1930s/40s, Harold Sanborn

Steam Shovels and Snogos Digging Deep at Rocky Mountain National Park

Fall River Road was the predecessor to Trial Ridge Road. Neither road has ever even been opened during the winter, but both have presented huge challenges when it comes to opening them in the spring. Early snow removal efforts in the park started with steam shovels and regular snowplows. Snogo plows were used from the 1930s and onward into the modern day in order to open the road in the spring.

A Snogo from Rocky Mountain National Park is included in the National Register of Historic Places. The drawing below by Nathan Junkert demonstrates some of the history of snow removal in the park.

historical illustration of snowplows in Rocky Mountain National Park
Historic American Engineering Record, National Park Service, Nathan Junkert, 2000. View Full Size

The first Snogo was purchased to open and maintain Trail Ridge Road in 1931.10

The rotary snowplow below was photographed in Rocky Mountain National Park during the 1950s, likely in the Alpine Visitor Center parking lot that is located on Trial Ridge Road. This image has been scanned from a slide that is held in the Coloradotopia archives.

Snogo rotary snowplow in rocky Mountain National Park in year 1957
Snogo in Rocky Mountain National Park in 1957

Year-Round Crowns

Some passes were kept open year-round during the 1800s by using sleighs instead of wagons. It would not be until the 1930s that any of the major mountain passes were able to stay open for automobiles, without a seasonal closure. Here are the winners of the year-round crowns:

1929-’30 Tennessee Pass – This pass was able to stay open throughout the season for the first time in the winter of 1929-’30. This required the work of 4 snowplows, including 1 large rotary snowplow.11

1932-’33 Berthoud Pass – Berthoud Pass was able to stay open through the winter for the first time in 1932-’33, despite having tried and come close in prior years. $60,000 of new equipment, including a Snogo rotary plow was brought to Berthoud Pass in order to keep it open for the winter.12

1936-’37 Rabbit Ears Pass and Wolf creek Pass – The winter of ’36-’37 was the fist time that Rabbbit Ears Pass stayed open for the full winter. This was also the same season that Wolf Creek Pass stayed open year-round for the first time.

1938-’39 Loveland Pass – This pass, along with some of the others, was kept in use during the winters in the 1800s by using sleighs instead of wagons. The first year that the modern highway over Loveland Pass was open for automobiles was the winter of 1938-’39.13

Snogo rotary snowplow working on Berthoud Pass circa 1940s
Bethoud Pass, c. 1940, Harold Sanborn

How much did early rotary snowplows for highway use cost?

These plows were cheaper than the larger railroad plows that had been produced for several decades. Jackson County trialed a rotary snowplow in January of 1931, and the cost of the rotary plow was expected to be $12,000 if the trials were successful. The plow could be mounted on the front of a powerful truck. A flanger-type blade would break up and elevate the snow into the fan, which then blew the snow out of the way. The trials were deemed unsuccessful, although the manufacturers offered to have one of their service men operate the plow in further trials.14

Into the Modern Era...

rotary snowplow clearing snow on Trail Ridge Road
A modern auger-style snowplow clears the snow on Trail Ridge Road, 2004, Ken Papaleo

By the 1950s, almost all of Colorado’s major mountain highways were staying open year-round. The list of passes staying open during the winter at that point was virtually the same as the present-day list.

old Snogo snowplow sitting outside on Monarch Pass in Colorado
An aging Snogo on top of Monarch Pass

References & Credits

Images Credits: Coloradotopia Archives, Library of Congress [LC-DIG-ppmsca-53298], Denver Public Library/Rocky Mountain News Collection/Ken Papaleo [RMN-020-5073], Center for Land Use Interpretation | More info

  1. The Holy Cross Trail, Volume 14, Number 5, March 29, 1924, p. 1
  2. The Eagle County Blade, February 16, 1899, p. 3.
  3. The Rocky Mountain News (Daily), Volume 30, February 27, 1889, p. 6.
  4. The Herald Democrat, January 3, 1888, p. 4.
  5. The Steamboat Pilot, April 13, 1928, p. 1.
  6. The Herald Democrat, March 27, 1923, p. 6.
  7. The Routt County Sentinel, September 29, 1922, p. 1.
  8. The Rocky Mountain News (Daily), Volume 65, Number 135, May 14, 1924, p. 15.
  9. The Steamboat Pilot, June 11, 1924, p. 1.
  10. Brothers, A. (2017, May 30). Photos: Pikes Peak Highway, Mount Evans Byway, Trail Ridge Road. The Denver Post. https://www.denverpost.com/2017/05/30/pikes-peak-highway-mount-evans-byway-trail-ridge-road-photos/
  11. The Steamboat Pilot, May 9, 1930, p. 8.
  12. The Colorado Transcript, Number 10, January 5, 1933, p. 1.
  13. The Holy Cross Trail, Volume 29, Number 14, April 7, 1939, p. 1.
  14. The Steamboat Pilot, March 20, 1931, p. 3.