Complex sentence: Mr. Prospector's sire was Raise a Native, a son of Native Dancer and out of the mare, Gold Digger, a daughter of Nashua who was sired by the great Nearco.
Split into simpler sentences: Mr. Prospector's sire was Raise a Native, a son of Native Dancer. He was out of the mare Gold Digger, a daughter of Nashua who was sired by the great Nearco.