Plains sharp-tailed grouse nesting habitat was evaluated on the Grand River National Grasslands (GRNG) in northwest South Dakota, in the spring and summer of 2009 and 2010. Experiment #1 was conducted across the GRNG with hens and males trapped at 11 different lekking sites in 2009 and 2010. Study objectives were to 1) evaluate sharp-tailed grouse nest site selection based on habitat and describe vegetation composition and visual obstruction readings (VOR), 2) compare the use of semi-variance statistics to the commonly used co-efficient of variation to determine patch selection by sharp-tailed grouse, and 3) provide an example of how semi-variance statistical techniques can be used by wildlife scientists to evaluate habitat selection and patch size determination. Experiment #2 was designed to evaluate survivorship of female and male sharp-tailed grouse, and sharp-tailed grouse nests on the GRNG in the spring and summer of 2009 and 2010. Study objectives were to I) estimate nest survival rates of sharp-tailed grouse on the GRNG in northwest South Dakota, 2) evaluate the effects of abiotic and biotic factors on nest survival rates, and 3) estimate survival of male and female grouse during the nesting season. VOR data was collected at 275 random transects (143 in 2009 and 132 in 2010) and 46 used (nests) transects (22 in 2009 and 24 in 2010). Sharp-tailed grouse were trapped and fitted with necklace style transmitters. Over the two year study 163 sharp-tailed grouse were trapped and 100 of these individuals were fitted with radio collars ( 44 males and 56 females). Nests were monitored to determine fate. There was a difference (P:S0.05) in patch selection compared to what was available in 2009, but no difference in 2010. The comparison of semi-variance (SV) analysis to co-efficient of variation (CV) provided a conflicting report as SV showed selection for variability, while the CV showed a selection for low variability and a uniform height distribution of vegetation. Overall 41 of 56 collard hens initiated nests, with 5 hens initiating a second nest following the predation of her first (18 initial nest and 4 re-nests in 2009, and 23 initial nests and 1 re-nest in 2010). Vegetation measurements were taken at 46 nest sites. Overall, nest survival was 30% (29% in 2009 and 31 % in 2010). The best model for nest survival included maximum vegetation height and percent grass canopy cover as vegetation variables most related to nest survival. Nest survival increased with an increase in the maximum vegetation height and with increasing canopy cover of grass. All other models that included other vegetation characteristics as variables were not well supported (i.e., >2 MICc units). The constant survival model had more support than any of the models that included time dependent variables such as linear trend of time, maximum daily temperature, and nest age. The model that included a linear trend of time was the best time dependent model (MICc = 1.21 ). The model that combined a linear trend of time with the best vegetation model, maximum vegetation height plus percent canopy cover of grass, received less support than the vegetation model alone (MICc 0.77). Survival of male and female sharp-tailed grouse was 49% and 65%, respectively. We recommend managers develop strategies to maintain patches of tall dense vegetation structure. Patches of tall grass cover is an important component to sharp-tailed grouse nesting habitat. Thus, we recommend that management of grazing and use of mechanical treatments that leave patches of tall dense stands of grass in grass dominated ecosystems are beneficial to nesting sharp-tailed grouse.