Sharp-tailed grouse habitat on the Dakota Prairie Grasslands are assessed by habitat structure with the use of the Robel pole to measure visual obstruction readings (VOR). The purpose of this study was to determine 1) if all selected ecological sites (loamy, thin loamy, and claypan) are biologically capable of producing high structure (VOR > 3.5 in) with 3 years of protection from livestock grazing and 2) if strong and consistent correlations exist between standing crop and visual obstruction among ecological sites and across years. Results showed that 1) all selected ecological sites were biologically capable of producing high structure, 2) strong correlations between standing crop and visual obstruction were not consistent among ecological sites and across years, 3) year effects were evident in plant community composition, and 4) 2,534 kg/ha (se ± 205.3) of standing crop provides the mean threshold to determine if the selected ecological sites are biologically capable.