"These plains east of the Hudson's Bay Company (HBC) stocade have seen many uses over time. During the early to mid-19th century they contained HBC agricultural fields and pastures. Then in 1856 the U.S. Army established an ordnance reserve on a portion of the plain, although American settlers provided constant annoyance by challenging claims to the land.

Standing in this spot in 1918, one would have been inside the huge, circular, concrete waste burner of the U.S. Army Spruce Production Division's Vancouver Spruce Mill. The mill covered 50 acres of the plain south of today's East Fifth St., including the remains of the HBC's stockade. The Spruce Mill was built to meet the World War I Allied forces' need for millions of board feet of lumber for airplane components.

Today, a portion of the plain has returned to a natural state, but the Spruce Mill's legacy of flight still resonates at nearby Pearson Field."


Source:    Fort Vancouver National Park Service Information Sign, visited April 2017.

"During World War I, the Army Signal Corps built and operated a very large saw mill on this site. The mill produced sitka spruce lumber to manufacture military aircraft. Although the military had cooperated with private industry before the Spruce Production Division (SPD) was formed, the SPD was an ambitious effort to use U.S. industrial technology to manufacture a strategic material. To meet the wartime production goal of 100 million board feet of sitka spruce lumber, the Army planned to build two saw mills in Washington and one in Oregon. It built thirteen separate railroads, commandeered hundreds of acres of spruce timber land, and assigned over 30,000 regular Army troops to duty in the logging camps and lumber mills of the Pacific Northwest. ...

The huge Vancouver Spruce Mill was the centerpiece of spruce lumber manufacturing in the Northwest. Work on the Vancouver mill began on December 14, 1917, and the mill was operating by February 7, 1918. The last full month of production was October, 1918. By then, the Vancouver mill was cutting and shipping one million board feet of spruce each working day. ...

Where Did the Spruce Come From?

To supply the Vancouver mill with as much as one million board feet of spruce every working day, the Spruce Production Division tapped a network of spruce-producing forests and mills on the coast of Oregon and Washington. ... The Army helped the industry meet the new demand for spruce by building thirteen logging railroads to get the logs out of the woods and to the mills. After the mill at Vancouver was up and running, the SPD built additional mills for spruce board production at Toledo, Oregon, and Port Angeles, Washington.

Bringing in the Spruce:

The trains loaded with spruce from the coastal forests rolled into the mill on Spur A, parallel to 5th Street, immediately north of here. A self-propelled steam crane running on a separate track lifted the spruce "cants" off the rail cars onto flat carts. Then the mill crew wheeled the cants into the mills to be cut up for aircraft timbers. The mill was capable of processing an enormous amount of spruce. If each rail car held 10 thousand board feet of spruce, 100 railcars would have to be unloaded each day to meet the production goal of one million board feet. ...

To streamline the manufacturing process, the spruce logs were cut into large timbers called "cants" at civilian mills on the coast. ...

The Dry Kilns:

To the east of the Main Mill building ... was the Spruce Mill's dry kiln system. Here the best of the spruce lumber was dried before shipment to the aircraft factories.

After the spruce was milled to specific dimensions in the cut-up plant, boards selected for wing-beams and other critical aircraft parts were brought to the dry kiln and blasted with steam at temperatures so high as 160 degrees F. The kiln held 39,000 board feet of wing-beam stock in each of its 24 chambers, for a total of 936,000 board feet. Each "charge" of spruce took 18 days to cure however, so the kiln could not keep up with the Mill's production rate. The excess lumber was dried in the open air, or shipped green ....

The Loading Sheds:

In this area, which is south and west of the Main Mill building, was an extensive set of loading sheds.

Finished lumber was loaded into boxcars here for shipment to aircraft factories in the U.S., or to the Allied forces' aircraft factories in Europe. About 70% of the spruce went to aircraft plants in Britain, France, and Italy. ...

Making Aircraft for the War:

Approximately 4,000 aircraft were made in the U.S. for the war. More were made in Europe, but the amount of sitka spruce cut by the Spruce Production Division far exceeded the need. If each airplane required 2,500 board feet of spruce, the 143 million board feet that the SPD produced would have made 57,000 Allied aircraft. ...

Why Sitka Spruce?

Spruce is a common species of tree, found in America, Europe, and Asia. Engineers determined that sitka spruce, growing on the coast of Oregon, Washington, British Columbia, and Alaska, had the highest tensile strength of any spruce species. Also, sitka spruce grew larger than other species, so the amount of defect-free lumber was greater. ...


Source:    U.S. National Park Service, 2010, "Spruce Trail Guide: The U.S. Army Spruce Production Division Mill", brochure obtained during visit April 2017.

Vancouver Supplies the Air War

The Spruce Mill, also known as the "Cut-Up Plant," was built in 45 days and covered more than 50 acres. At peak, it was producing a million board feet of lumber every 24 hours for Allied airplane manufacturers. This HO scale (1/87) model is a replica of the mill as it looked during the summer of 1918. National Park Service volunteer Dr. Gary Brooks donated 1,200 hours to research and build this model, based on historic records, photographs, and maps.

On this map, Spruce Mill buildings and rail lines are shown in blue. Modern buildings and landscape features are outlined. Your current location is marked with a yellow triangle."


Source:    Spruce Mill Model information sign, Pearson Air Musueum, visited April 2017.

Milling Lumber Produces Mountains of Wood Waste:

We do not know what the completed Spruce Mill burner looked like, because no photos or plans of the burner have survived. In fact, the burner may never have been completed. We know that it was still under construction in the summer of 1918. ...

If the mill operated at 90% efficiency, it would have produced about 300 cubic yards of waste each day. ...

Spruce Mill Archaeology:

[The] sawdust burner [was] located in the northeast corner of the original Hudson's Bay Company stockade. Army Engineers built the Spruce Mill on the old Hudson's Bay stockade site. Some Hudson's Bay and early military artifacts have been covered and protected by fill from the construction of the Spruce Mill. In 1966, the Hudson's Bay Company stockade was restored. Some foundations of Spruce Mill structures, including the planing mill and loading platforms, are buried beneath the retored stockade. ...


Source:    U.S. National Park Service, 2010, "Spruce Trail Guide: The U.S. Army Spruce Production Division Mill", brochure obtained during visit April 2017.

At full operation, the cut-up plant ran 24 hours each day, in three 8-hour shifts. 3,000 Spruce Production Division soldiers worked at the Spruce Mill. ...

Daily Life at the Spruce Mill:

At the peak of operations in September and October, 1918, 3,042 soldiers, worked at the mill. A few fortunate men lived in wooden huts of "cantonments" ... but most lived in pyramid-shaped tents pitched in rows to the north of the Spruce Mill. ...

Tent City:

For most of America's involvement in the war, SPD soldiers lived in [tents]. They were pitched on vacant ground north of the Spruce Mill, forming a sea of white on the slope north to the Vancouver Barracks Parade Ground. Each tent was equipped with a heating stove, and some had wooden floors and side walls. ...


Source:    U.S. National Park Service, 2010, "Spruce Trail Guide: The U.S. Army Spruce Production Division Mill", brochure obtained during visit April 2017.