First off, Gates of Lodore is the name for the canyon at this section of the Green River. In 1869 Andrew Hall, a member of John Wesley Powell's expedition, named The Gates of Lodore after a poem called, "The Cataract of Lodore," by Robert Southey. So there's your history lesson.
Second, the campground is quite nice with plenty of spots, plenty of parking and plenty of bathrooms. The ranger station is right there too if you need help.
Third, rafting is great here. If you're a private boater make sure you have your permit. The beach to the water can be quite long and the sand is bad, vehicles get stuck in it. Luckily the place has a moon rover looking thing you can use to load your boat on and take to the water. Check the photo to see what it's like.
Fourth, there's a short hike here that takes you closer to the Gate of Lodore canyon and it's really pretty. So there's that to enjoy as well.