Yes, there are several campgrounds in Poudre Canyon that offer first-come, first-served camping. Some of these campgrounds include Ansel Watrous, Stove Prairie, and Mountain Park. However, it is recommended to arrive early, especially during peak camping season, as these sites can fill up quickly. Keep in mind that some campgrounds may also have a limited number of reservable sites available. Always check the specific campground for its policies and current availability before planning your trip.