The competitiveness of biomass as a source of energy supply strongly depends on biomass supply chain. This paper presents a discrete mathematical model of mallee biomass production, harvest, on-farm haulage, and road transport to a central bioenergy plant. The model has been specially designed to assess the performance of mallee biomass production in the "wheatbelt" agriculture area of Western Australia (WA). It is based on a continuous, integrated, and streamlined supply chain from farm to the bioenergy plant and evaluations based on the road systems in the same region. The delivered cost of mallee biomass strongly depends on feedstock collection distance, farm size (a surrogate for on-farm haulage distance), road transport scenario, and proportion of the land planted to mallee. The results indicate that although the mallee biomass in WA is planted in a well-ordered distribution through alley farming, it is clear that transport, including on-farm haulage and road transport, can make significant contributions to the total cost of mallee biomass delivered to a bioenergy plant. For the same distance, biomass on-farm haulage is considerably more expensive than biomass road transport, and its cost increases substantially with farm size. For small plants requiring short feedstock collection distances, on-farm haulage cost dominates the total biomass transport cost. The importance of biomass road transport increases with the feedstock collection distance (i.e., plant capacity). Long-distance biomass road transport is not feasible, and a mallee-based bioenergy plant will still be constrained in scale and most likely located in regional centers. Strategies for reducing the delivered cost of mallee biomass include (a) locating the biomass processing plant near areas of high planting density; (b) managing or upgrading on-farm tracks and roads, planning seasonal schedules, or improving haulage efficiency to minimize on-farm haulage cost; and (c) integrating road transport into the business of either biomass growers or biomass processing plant owners, rather than that of independent third parties as transport service providers because separate ownership leads to increased cost.