Net periodic dry weight and volume production of stemwood were computed from stem analysis and wood density samples for 18 red pine (Pinus resinosa Ait.) plantations on well-drained, predominantly sandy soils in northern lower Michigan. Cumulative production on sample trees was related to current tree diameter breast height; and regression equations were then used to compute net cumulative production per acre from the stand tally. Net stemwood weight (and volume) per acre at age 35 years ranged from 24,200 lbs (1150 cu ft) on the poorest site, to 149,900 lbs (7200 cu ft) on the best site. Stemwood production was related to five soil profile characteristics by regression methods. Productivity increased with increasing amounts of silt plus clay in the finest textured layer and increasing thickness of the A + B horizon; it decreased as depth to the finest textured layer increased. Prediction equations containing these factors accounted for 69 and 71 percent respectively of the variation in estimated weight and volume at age 35.