The chart is zoomed in on the area where color changes occur - the chart is 65 rows tall and 160 stitches wide, but the color changes only occur in the center 120 stitches. I used this chart to make a blanket for my sister that was a total of 195 rows tall and 160 stitches wide - I started using the chart somewhere around row 100, then added more rows of blue after finishing the charted portion. You could do this in Tunisian or single crochet. I chose Tunisian as it gives a cleaner edge.