I just returned from Mule Days camping in the cow pasture.
People that tried bringing wagons across with horses had plenty of trouble and many changed over to different critters.
Mules were the fastest option. Those that could afford brought two teams and rested one each day.
Oxen were slower but very dependable. People had great affection for their oxen. Many were shod in the old days.
I was helping a friend find a team of mules this week.
One fo the great books recently is a new trip on "The Oregon Trail" by R Buck.