Walk
According Wikipedia: 4 miles (6,4 km) per hour;
According "The West that was" edited by Joe Lansdale: 4 miles (6,4 km) per hour.
Trot
Wiki: 8 miles (13 km) per hour;
TWtw: 8 miles (13 km) per hour.
Gallop (canter)
Wiki: 10 to 17 miles (16-27 km) per hour;
TWtw: 12 miles (19 km) per hour.
Full gallop
Wiki: 25 to 30 miles (40 to 48 km) per hour;
TWtw: 16 miles (25 km) per hour.
"Obviously, the terrain, weather, and condition of the horses significantly affected the rate" (The West that was, pag. 126).
According Wikipedia: 4 miles (6,4 km) per hour;
According "The West that was" edited by Joe Lansdale: 4 miles (6,4 km) per hour.
Trot
Wiki: 8 miles (13 km) per hour;
TWtw: 8 miles (13 km) per hour.
Gallop (canter)
Wiki: 10 to 17 miles (16-27 km) per hour;
TWtw: 12 miles (19 km) per hour.
Full gallop
Wiki: 25 to 30 miles (40 to 48 km) per hour;
TWtw: 16 miles (25 km) per hour.
"Obviously, the terrain, weather, and condition of the horses significantly affected the rate" (The West that was, pag. 126).