Tosefta untuk Ulangan 27:2

The blessings and the curses are those that Israel pronounced when Israel crossed the Jordan, as it is said (Deut. 27:2), "And it shall be on the day that you cross the Jordan." How did Israel cross the Jordan? On every [other] day the Ark would travel after two banners, but on this day it traveled in front, as it is said (Josh. 3:11), "Behold, the Ark of the Covenant of the Master [of the whole world is passing before you]." On every [other] day the Levites were carrying the Ark, but on this day the priests carried it, as it is said (Josh. 3:13), "When the soles of the feet of the priests [bearing the Ark of God] came to rest, etc." Rabbi Yosei says, in three places the priests carried the Ark: One, when Israel crossed the Jordan; and one, when they circled around Jericho; and one, when they returned it to its place (i.e., in the Holy of Holies).

It comes out that you can say there were three sets of stones: One that Moses erected on the banks of the Jordan River on the Plains of Moab (Deut. 27:2), and one that was under the feet of the priests [in the middle of the Jordan] (Josh. 4:3), and one that they brought over with them (Josh. 4:5).