▁plate aux . ▁With ▁the ▁exception ▁of ▁the ▁area ▁around ▁the ▁lim estone ▁plate au ▁of ▁the ▁H oh er ▁If en , ▁the ▁western ▁mountain ▁ranges , ▁including ▁the ▁All g äu ▁Al ps , ▁form ▁mountain ▁ch ains ▁unlike ▁the ▁eastern ▁plate au ▁ranges , ▁such ▁as ▁the ▁Lo fer ▁Stein berg ▁mountains . ▁ ▁The ▁only ▁mountain ▁chain ▁proper ▁runs ▁through ▁the ▁south - e astern ▁and ▁eastern ▁part ▁of ▁the ▁All g äu ▁Al ps ▁and ▁forms ▁the ▁Aust ro - G erman ▁border . ▁This ▁main ▁chain , ▁with ▁a ▁brief ▁inter ruption ▁in ▁the ▁area ▁of ▁R au heck , ▁is ▁built ▁from ▁a ▁very ▁w ides p read ▁rock ▁formation , ▁known ▁as ▁main ▁dol om ite . ▁It ▁begins ▁at ▁the ▁s addle ▁of ▁the ▁Sch ro fen ▁Pass ▁at ▁the ▁head ▁of ▁the ▁R appen al pen ▁valley ▁and ▁runs ▁largely ▁in ▁a ▁straight ▁course ▁to ▁the ▁Ober jo ch ▁s addle . ▁ ▁A ▁large ▁number ▁of ▁side ▁rid ges ▁branch ▁off ▁the ▁main ▁chain . ▁He ading ▁south west ▁are ▁the : ▁Ho he ▁L icht ▁and ▁Pe isch el ▁Group ▁to ▁the ▁south ▁and ▁east , ▁the ▁H imm el sch ro fen ▁r idge ▁to ▁the ▁north , ▁the ▁Horn bach ▁Range ▁to ▁the ▁east , ▁the ▁Für sch ie ßer ▁to ▁the ▁north west , ▁the ▁K eg el kö p fe ▁to ▁the ▁north west , ▁the ▁Hö f ats ▁Group ▁to ▁the ▁north west , ▁the ▁K