Due to limitations of land area for growing biomass for large biofuel conversion facilities in the upper Midwest and the high cost of feedstock transportation in regions that have lower biomass density, it would be beneficial to develop a small scale, less expensive, and localized conversion facilities that require less feedstock and have lower feedstock transportation costs. Woody species (brush) growing on semi-arid non-cultivated lands (rangelands), such as mesquite (Prosopis glandulosa) and juniper (Juniperus spp.), may have potential as bioenergy feedstock. These species occur on over 20 million ha in Texas alone and can achieve standing biomass of 50 dry metric tons ha1 [4]. They are perceived as noxious plants that are detrimental to rangeland ecosystems and their removal and use as a bioenergy feedstock would result in improvements in ecosystem quality as well as services from these lands such as increased income from livestock grazing [5]. These species may be ideal candidates to produce syngas and bio-oil in small scale gasification units that can be located near the fuel source to reduce feedstock transport costs.