In a great part of that territory, farmers must depend on irrigation water from the snows or rains that are trapped by the mountains.
(farmers; must depend; on irrigation water from the snows or rains; L:In a great part of that territory) (the snows or rains; are trapped; by the mountains)
farmers the snows or rains
must depend are trapped
on irrigation water from the snows or rains L:In a great part of that territory
by the mountains