Among bioenergy feedstocks, timber and crop residues offer low marginal cost of production and low risk of indirect land use change that can boost greenhouse gas emissions. The potential economic supply depends on the willingness of producers to make residues available. Previous studies show that willingness to supply annual crop residues depends upon prices, attitudes toward bioenergy, biophysical setting, and demographic traits. For timber residues, a smaller literature on non-industrial private forest owners found similar results, but little is published about what drives the availability of timber residues from large public and commercial forests. Combining survey data on small-scale forest owners with interview data on managers of large-scale commercial, public and conservancy-owned forests, we find that willingness to provide timber residues varies by landowner type. At prices of $4-11 Mg -1, most commercial forest managers are willing to permit residue removal at timber harvest. M higher prices of $13-26 Mg (-1), up to half of non-industrial private forest owners are also willing. However, among managers of large-scale public and conservancy forests, environmental conservation rules and/or insufficient motivation largely prevent the removal of timber residues at harvest. Future projections of timber residue supply should explicitly account for differences in the willingness of each type of forestland owner to supply residues as a bioenergy feedstock.