Complex sentence: The Commission eventually confirmed 604 of the 813 claims they received, but the cost of litigation, surveys, taxes and permits forced some of the larger Californio Rancho owners to lose part or all of their property.
Split into simpler sentences: The Commission eventually confirmed 604 of the 813 claims they received. The cost of litigation, surveys, taxes and permits to prove rancho ownership forced some of the larger Californio Rancho owners to lose part or all of their property.