The undulating river pattern is an attractive addition, and surprisingly easy to add to any standard sock pattern.

Turkish cast-on 13. Started 11 stitch “river ribbing” while I worked my usual toe, increasing to 62 stitches. Got a bit off track with my gussets and heel, working 15 gusset increases on alternate rounds, spaced 19 stitches apart on the base of the sole. I turned the heel and worked the flap on those same 19 stitches, making a narrower flap.