▁of ▁Washington ▁and ▁the ▁Central ▁Valley ▁of ▁California ▁are ▁also ▁pra i ries . ▁The ▁Canadian ▁Pra i ries ▁occup y ▁vast ▁areas ▁of ▁Man it oba , ▁S ask atch ew an , ▁and ▁Al berta . ▁ ▁Et ym ology ▁ ▁According ▁to ▁The odore ▁Ro ose vel t : ▁Pra irie ▁is ▁the ▁French ▁word ▁for ▁me adow ; ▁the ▁root ▁is ▁the ▁Latin ▁pr atum ▁( same ▁meaning ). ▁ ▁Form ation ▁▁ ▁The ▁formation ▁of ▁the ▁North ▁American ▁Pra i ries ▁started ▁with ▁the ▁u pl ift ▁of ▁the ▁Rock y ▁Mountains ▁near ▁Al berta . ▁The ▁mountains ▁created ▁a ▁rain ▁shadow ▁that ▁resulted ▁in ▁lower ▁precip itation ▁rates ▁down wind . ▁ ▁The ▁parent ▁material ▁of ▁most ▁pra irie ▁soil ▁was ▁distributed ▁during ▁the ▁last ▁gla cial ▁advance ▁that ▁began ▁about ▁ 1 1 0 , 0 0 0 ▁years ▁ago . ▁The ▁gla ci ers ▁expand ing ▁south ward ▁sc rap ed ▁the ▁landscape , ▁pick ing ▁up ▁ge olog ic ▁material ▁and ▁level ing ▁the ▁terrain . ▁As ▁the ▁gla ci ers ▁retre ated ▁about ▁ 1 0 , 0 0 0 ▁years ▁ago , ▁it ▁depos ited ▁this ▁material ▁in ▁the ▁form ▁of ▁till . ▁Wind ▁based ▁lo ess ▁depos its ▁also ▁form ▁an ▁important ▁parent ▁material ▁for ▁pra irie ▁so ils . ▁ ▁T all gr ass ▁pra irie ▁evol ved ▁over ▁tens ▁of ▁thousands ▁of ▁years ▁with ▁the ▁dist urban ces ▁of ▁gra zing ▁and ▁fire . ▁Native ▁ung ul ates ▁such