Read this: The variances in nomenclature in the region spanned by the Alps makes classification of the mountains and subregions difficult, but a general classification is that of the Eastern Alps and Western Alps with the divide between the two occurring in eastern Switzerland according to geologist Stefan Schmid, near the Splugen Pass.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): What makes the classification of the mountains and subregions difficult?
The variances in nomenclature