Dan congatulations on your engagement. Try the abandoned quarry directly across from the Perry Park campground. There area about 10 or so spots back in there that may suit your needs if others are not camping there. This would probably be the closest area to the La Plata trailhead. The dirt road leading up to the Mt. Elbert trailhead has some spots as well but is further from your objective. Please be respectful of the area and pack out your trash and bury your waste.