Quality of nesting habitat surrounding the lek is the most important factor in population success. Adequacy of cover is critical for nesting. Too little can exist: where 13% was the average total crown cover on Idaho range, nests were located where average cover was 17%. No hens nested in the most arid, open areas with less than 10% total shrub cover. Too much also can occur: average shrub cover at 87 nest sites was 18.4%, and in more dense cover, greater sage-grouse did not nest where total shrub cover was greater than 25%. In Utah, no nests occurred where threetip sagebrush cover exceeded 35%.