▁observ ational ▁( making ▁sure ▁current ▁habitat ▁is ▁maintained ) ▁to ▁more ▁hands ▁on ▁approach . ▁The ▁management ▁of ▁le kk ing ▁habitat ▁and ▁winter ▁habitat ▁are ▁not ▁as ▁clearly ▁defined ▁in ▁the ▁literature ▁as ▁nest ing ▁and ▁bro od ▁re aring ▁habitat ▁assess ment ▁and ▁management . ▁The ▁development ▁of ▁the ▁Rob el ▁pole ▁and ▁cover ▁bo ards ▁has ▁become ▁a ▁key ▁tool ▁in ▁habitat ▁assess ment ▁providing ▁land ▁man agers ▁a ▁means ▁to ▁invent ory ▁and ▁study ▁habitat ▁prefer ences ▁based ▁on ▁veget ation ▁structure ▁and ▁density . ▁The ▁Rob el ▁pole ▁has ▁become ▁the ▁more ▁fav ored ▁of ▁the ▁two ▁methods ▁in ▁recent ▁years ▁for ▁habitat ▁assess ment . ▁The ▁United ▁States ▁Forest ▁Service ▁( US FS ) ▁uses ▁visual ▁obst ruction ▁read ings ▁( V OR ) ▁to ▁set ▁stock ing ▁dens ities ▁for ▁cattle ▁based ▁on ▁the ▁current ▁years ▁standing ▁resid ual ▁veget ation ▁. ▁This ▁method ▁is ▁currently ▁conducted ▁on ▁the ▁US FS ▁Little ▁Missouri ▁Gr ass lands , ▁She y enne ▁National ▁Gr ass lands , ▁C ed ar ▁River ▁National ▁Gr ass land , ▁and ▁Grand ▁River ▁National ▁Gr ass land , ▁all ▁found ▁in ▁the ▁Dak ota ▁Pra irie ▁National ▁Gr ass lands ▁in ▁North ▁and ▁South ▁Dak ota ( For est ▁Service , ▁Northern ▁Region ▁( US DA ). 2 0 0 1 ) ▁. ▁The ▁Rob el ▁pole ▁is ▁a ▁non - dest ruct ive ▁method ▁for ▁invent ory ing ▁veget ative ▁bi om ass ▁( Rob el ▁ 1 9 7