Complex sentence: The kiln operation lasted for less than three years, employing 150 to 200 people at its peak, and had a monthly output estimated at 44,000 to 50,000 bushels of charcoal.
Split into simpler sentences: The kiln operation lasted for less than three years, employing 150 to 200 people at its peak. The kilns had a combined monthly output estimated at 44,000 to 50,000 bushels of charcoal.