Complex sentence: With their wagon, they had two yokes of oxen, one of cows and an extra cow, they were accompanied by William Buck, who would remain with them much of the way before separating from them to go to California.
Split into simpler sentences: With their wagon, they had two yokes of oxen, one of cows and an extra cow. They were accompanied by William Buck, who would remain with them much of the way before separating from them to go to California.