Abstract. Perennial grasses and corn stalks can supply abundant lignocellulosic feedstock in the northern Great Plains of the U.S. There is a need to understand the mechanical properties of these crops for better handling and processing of biomass feedstocks in bioprocessing industries. The objectives of this research included determination of tensile and shear stresses of big bluestem, corn stalk, intermediate wheatgrass, and switchgrass stems and measurement of specific tensile and shear energies during tensile and shear failure. A high-capacity MTI-100K universal testing machine equipped with adapted tensile clamps and a specially designed and fabricated double-shear device were used for tensile and shear testing. Ultimate shear stresses were not statistically different for big bluestem, corn stalk, and intermediate wheatgrass, with values of 7.33, 8.53 and 6.23 MPa, respectively, which were less than switchgrass at 13.39 MPa (p