The Upper North Fork River in Colorado is a Class III run that is best floated in the spring and early summer when the water levels are high. The main obstacles on this run include several steep drops, tight turns, and a few small rapids that require precise maneuvering. The recommended flow for this section of water is between 500 and 1,000 cfs. However, during peak runoff season, the water levels can reach up to 2,000 cfs, making the river more challenging. Overall, the Upper North Fork River is a fun and exciting run that is best suited for intermediate paddlers with some experience navigating Class III rapids.