Poudre River Whitewater Park replaced an aging, unsafe diversion structure in downtown Fort Collins with engineered drops designed by S2O Design, built to work across flows from about 75 cfs up past 2,000. At low water the Poudre here is mellow enough for tubing and flatwater paddleboarding, and once spring snowmelt kicks in, the same structures turn into real surf features for kayakers and stand-up surfers. The project doubled as flood control for the city and included a first-of-its-kind fish passage design, so it's as much civic infrastructure as playground. Parking, trails, and access run right through downtown, making this one of the easiest put-ins on the whole river.