▁up stream ▁to ▁its ▁confl u ence ▁with ▁the ▁Kr umb ach ▁near ▁War th ▁( Vor ar l berg ). ▁The ▁Kr umb ach ▁forms ▁the ▁boundary ▁as ▁far ▁as ▁the ▁Ho cht ann berg ▁Pass . ▁It ▁then ▁continues ▁along ▁the ▁Se eb ach ▁and ▁B reg en zer ▁Ach ▁streams ▁to ▁Au - Re hmen . ▁ ▁The ▁border ▁of ▁the ▁All g äu ▁Al ps ▁in ▁the ▁west , ▁where ▁it ▁trans itions ▁to ▁the ▁B reg enz ▁Forest ▁Mountains ▁is ▁not ▁or ograph ically ▁distinct . ▁The ▁Al pine ▁Club ▁classification ▁of ▁the ▁Eastern ▁Al ps , ▁published ▁in ▁ 1 9 8 4 , ▁draw s ▁the ▁boundary ▁as ▁follows : ▁from ▁Au - Re hmen ▁along ▁the ▁Re h mer bach ▁up stream ▁to ▁the ▁St og ger ▁S addle . ▁Then ▁it ▁desc ends , ▁following ▁the ▁O ster gun ten bach , ▁the ▁Schön en bach ▁and ▁the ▁Sub ers ach ▁to ▁its ▁confl u ence ▁with ▁the ▁B reg en zer ▁Ach ▁and ▁along ▁this ▁river ▁to ▁where ▁it ▁joins ▁the ▁We iß ach ▁or ▁event ▁to ▁Lake ▁Const ance . ▁ ▁The ▁limit ▁of ▁the ▁All g äu ▁Al ps ▁in ▁the ▁north ▁is ▁ind ist inct . ▁One ▁more ▁restricted ▁variant ▁runs ▁from ▁the ▁confl u ence ▁of ▁the ▁We iß ach ▁and ▁B reg en zer ▁Ach ▁along ▁the ▁We iß ach ▁to ▁Ober st auf en . ▁It ▁then ▁continues ▁along ▁the ▁Kon stan zer ▁A che ▁and ▁the