The New Castle to Silt River Run on the Colorado River is an exciting and challenging route for experienced rafters. The Class II-III rapids make for a thrilling journey, but novice boaters should exercise caution. The best time to float this section of water is during the spring and early summer, when snowmelt increases the water flow to 2,000-5,000 CFS. River obstacles include several rocky outcroppings and small drops, so be sure to steer clear of these hazards. With its stunning scenery and exhilarating rapids, the New Castle to Silt River Run is a must-try adventure for seasoned river runners.