For the priests who bore the ark stood in the midst of the Jordan, until everything was finished that Yahweh commanded Joshua to speak to the people, according to all that Moses commanded Joshua: and the people hurried and passed over.
Some scholars have squirmed and quibbled over the setting up of two memorials, as mentioned here, declaiming on the stupidity of setting up a memorial where nobody would see it at the bottom of the Jordan, and other choice bits of human cavil.  Well, we thank God for the discernment of one like Pink, who has this: