An important and potentially underused source of biomass that could be utilized in energy production is from nonindustrial private woodlands. We employ the Theory of Planned Behavior to estimate the social availability of woody biomass as a function of landowner behavior intent, landowner characteristics, forest land characteristics, and biomass price on stated willingness to harvest biomass in conjunction with a commercial timber harvest. A mail survey was administered to 1109 nonindustrial private woodland owners in a 26county region in northeast Minnesota and northwest Wisconsin during the fall of 2009. Using binary logistic regression, we found payment level offered to harvest biomass plays a significant role in landowners’ decisions, but that non-monetary factors are also important. Landowner attitudes and opinions regarding soil impacts, aesthetics, and energy independence were important predictors of stated willingness to harvest. Social norms as manifested through the influence of neighbors were also significant. These findings expand existing research and are useful for profiling nonindustrial private woodland owners to identify sustainable sources of biomass to supply a burgeoning bioenergy sector in the Lake States.