By Mike Koshmrl, WyoFile.comSOUTH PASS—Corinna Riginos planted her feet among shin-high sagebrush that stretched out of sight. Still, places like South Pass and the Green River Basin are home to, by far, the largest and healthiest sagebrush tracts that are left. “There’s 16 million acres of core sagebrush area in Wyoming,” Riginos said. “They overpredict, at low levels of cheatgrass,” Larson said. Dropping into Sweetwater Canyon during the early-July outing, Riginos, Larson, Marsh and Joey Friedman descended toward several survey plots where they were confident they’d find cheatgrass.