Your first reading of chapter four should, once again, be a quick reading. The first time through is always about seeing the forest, not individual trees. Your primary goal is to get a feel for the flow of the narrative, the major characters, any key events, etc.
There are two parts to this section of the narrative - the portion involving the memorial stones and the crossing itself, and then a brief section about what happened immediately after the crossing. So as you read quickly through this chapter draw a horizontal line between the verses that mark that shift.
How big do you picture these stones as being? Keep in mind that they are each carried by one man. Do you picture them as bigger than a basketball? A bushel basket?
We’ll come back to explore some of the interesting details of this chapter, but for now, just read.