River is a re-introduction of a pattern originally published by Shibui (the pattern was then called "Stone" after the colorway of the yarn). I've re-christened the pattern "River" as the variegated colors remind me of the Naches River in eastern Washington. I lived right on the Naches for a couple years as a kid, and had many adventures exploring along it's banks. I was pretty sure that I would one day find part of a dinosaur skeleton, or at a least a dinosaur egg, bringing me world fame by age 9. Alas, neither the egg or the bones ever materialized.
About the sweater: River employs manipulation of the variegated yarn by alternating skeins every 2 rows/rounds over the sleeves and back, while using only one skein at a time over the front. This creates a variation in the patterning of the yarn in the different sections of the sweater.
To enhance this effect, the back and the sleeves are worked in a wide rib, while the front is worked in St st.
The neckline is finished with a rolled St st edging for a relaxed look; the sleeves are picked up from the armhole and worked down to the cuff, which reduces bulk at the armhole and makes the sleeve length easily adjustable.