ANNOTATION: In this paper the impact of combined biomass/fuel reduction harvests on the pools of forest fuels was analyzed to determine whether biomass harvest reduced the cost of mechanical fuel treatments. Two potential biomass harvest systems were tested in wildland-urban interface areas on the Superior National Forest in Minnesota. Both systems performed similarly in terms of cost and efficiency at harvesting biomass. It was found that the cost of biomass harvest was impacted by site conditions, forwarding distance, the number of units harvested with one machine haul, the number of machines that were hauled, acres harvested, and inclusion of roundwood. Income from the sale of biomass did not cover the costs of harvest and delivery. ABSTRACT: Combining biomass harvest with forest fuel reduction may reduce the costs of fuel treatments. Our objectives were to determine the impact of combined biomass/fuel reduction harvests on the pools of forest fuels and to determine whether biomass harvest reduced the cost of mechanical fuel treatments. We tested two potential biomass harvest systems in wildland-urban interface areas with forest fuel accumulations on the Superior National Forest in Minnesota. Both systems performed similarly in terms of cost and efficiency at harvesting biomass. Overall, the cost of biomass harvest was impacted by site conditions, forwarding distance, the number of units harvested with one machine haul, the number of machines that were hauled, acres harvested, and inclusion of roundwood. Income from the sale of biomass did not cover the costs of harvest and delivery; however, for hauls of less than 100 mi, harvest may reduce the cost of the fuel reduction activity.