Complex sentence: The association also purchased critical areas itself and to this day continues to maintain an extensive sanctuary system, of which the largest is the 26,000-acre Paul J. Rainey Sanctuary in Louisiana, acquired in 1924.
Split into simpler sentences: The association also purchased critical areas itself and, to this day, continues to maintain an extensive sanctuary system. The largest is the 26,000-acre Paul J. Rainey Wildlife Sanctuary in Louisiana, acquired in 1924.