Simpson has been in the forest products business since 1890.

Simpson Lumber Company, LLC has two operating subsidiaries:  Simpson Door Company and Simpson Tacoma Kraft Company, LLC.

Simpson Lumber Company, LLC owns production facilities in Tacoma, Shelton and Longview, Washington; Meldrim, Georgia; and Georgetown, South Carolina where it converts logs into dimension lumber.

Simpson Door Company, headquartered in McCleary, Washington, produces high-quality interior and exterior wood doors.

Simpson Tacoma Kraft Company, LLC manufactures bleached and unbleached kraft pulp and linerboard at its mill in Tacoma, Washington. The mill employs some of the most advanced paper recycling techniques available. The mill recycles some 500 tons of waste paper and boxes every day, turning it into high-quality packaging paper while improving the environment.