These are all in Northern Colorado/Southern Wyo, and longer (+8 miles) runs, but you asked.
Poudre - Upper Rustic below White Mile. This is one of the best III's out there. I've had friends from the East on it and they said it was some of the most continuous best III they've ever been on. You've got to hit it at above 3 ft on the rock. PM for more details, as there are tons of put-ins and take-outs.
Pourde - Upper Mish though Bridges late in the season (<3 - 2 on rock) will give you III+ -IV all day long.
Blue Below Green Mt. Res late in the season.
North Platte - North Gate Canyon - great wilderness canyon with one IV. Get on it between 1000-1800 cfs for your first time, otherwise it can get to you quickly. PM for more info as well.
You ARE a soul, you HAVE a body.