1849-1938 1860-1890 19th-century 19thcentury american-west americanbison americanhistory buffalo ca co conservation cultural-conflict environmentalism frontier frontiersman general georgebird great-plains grinnell hi history historyoftheamericas id indigenous-peoples militaryhistory mt national-parks native-americans nativeamerican natural-resources naturalist nv plains-indians preservation ranching regionalamericanhistory socialsciences ut west(ak westward-expansion wildlife wildlife-preservation worldwarii wy) yellowstone