Abstract A quantitative determination was made by the U. S. Forest Products Laboratory of the galactan in western larch woods and sawmill refuse to obtain data useful to those contemplating commercial ventures designed to produce and market various materials made of galactan. Galactan in the lateral roots of virgin trees ranged from approximately 11 to 23 percent, based on the weight of the oven-dry wood. The galactan content of slabwood from virgin-growth butt logs was found to be about 14 percent; from the middle logs, 4.2 to 10 percent; and from the top logs, about 5 percent. Butt logs from fire-killed virgin trees contained approximately 9 to 16 percent of galactan; the middle logs, 6.6 to 12.1 percent; and the top logs, 6.6 to 7.8 percent. Butt logs of stand thinnings contained from 3.8 to 5.3 percent of galactan; the middle logs, 2.1 to 3.5 percent; and the top logs, 2.2 to 3.1 percent.