Efficient methodologies for converting lignocellulosic biomass to replacements for or blends with gasoline, diesel, and/or jet fuel have the potential to reduce anthropogenic CO2 emissions while providing economic impetus for the expanded production of low-cost herbaceous and woody solids. Quantitative catalytic conversion of wood and cellulose to liquid and gaseous products in a single stage reactor operating at 300--350 °C and 160--220 atm is described. Little or no char is formed in the reactions. The reaction medium is supercritical methanol and the catalyst, copper supported on earth-abundant metal oxides, is inexpensive and easily prepared. The major liquid product is a mixture of C2--C6 aliphatic alcohols and methyl ether derivatives thereof, which are in principle suitable for use as a blend with, or replacement for, gasoline. General background, model studies, and a mechanistic hypothesis accounting for the conversion of high molecular weight polymers to low-boiling molecular entities are presented.