Whitewater rafting in Grand Canyon. NPS/Mark Lellouch. Colorado River below Nankoweap Creek. (River Mile 53.3) NPS/M.Quinn. There are different river trip opportunities through Grand Canyon National Park. 2 to 5 Day Noncommercial River Trips - Noncommercial trips that launch from Diamond Creek and takeout at Lake Mead typically are 2 to 5 days in length. Permits for these whitewater trips are available to the public starting one year in advance and are distributed on a first-come first-served basis.