From I-70, take the Georgetown Exit 228 and drive east on 15th St. to a traffic circle. Proceed 1/4 of the way through the circle and exit south onto Argentine St. Drive south on Argentine then turn left onto 11th St. Turn right onto Rose St. and head south into the main part of town. Continue all the way to 2nd St. where you'll turn left and will be on SH 381. This is the Guanella Pass Road. Follow it south for 2.7 miles to the turnoff for the Leavenworth Creek Road #352 (aka: FS 248.1). The turnoff is at the sharp curve of a second sharp switchback south of the Georgetown Reservoir by about .7 mile. If you come to Green lake, you have gone too far. The elevation at this turnoff is 9,520 and coordinates are: N 39° 40' 59.55" W 105° 42' 09.83". The road will initially parallel above the highway, then make a sharp switchback to head up to a crossing of Leavenworth Creek. After that crossing, there will be three more sharp switchbacks before the road joins the old railroad bed and stays on it all the way back to Waldorf. The most difficult & rockiest part of this road occurs before joining the railroad grade. If you make it to that point in whatever vehicle you're driving, you can likely make it to Waldorf. 4WD is not necessary for a railroad grade road, but good clearance is helpful.
It's about 5.6 miles up the Leavenworth Creek Road to the old site of Waldorf. The road is dirt/gravel and is best driven in at least a higher clearance vehicle. This area is very popular for weekend visitors in ATV's and various 4WD vehicles. When we lived on the Front Range prior to 1990, visiting up Leavenworth Creek was one of our favorite places to go for a quick mountain getaway. As you head up this road toward Waldorf, there will be several at-large primitive campsites if needed, most of them located well up canyon, but expect most all to be occupied on summer weekends. Park at the old mill site at Waldorf at the coordinates provided above. Many vehicles will stop here during the course of the day, so if you would like to park your vehicle a little more out of the way, continue south up the road another half mile to a small pond where you can park at: N 39° 37' 59.26" W 105° 46' 11.15". Beyond the Waldorf mine area, the road begins to deteriorate & become rockier. Parking at either of the two locations makes a good start location for Mt. Edwards, Wilcox, Square Top or Argentine.
The townsite of Waldorf was established in 1867, three years after a large silver vein/deposit was found in this area. John Edwards Wilcox, a Methodist minister, had much to do with the development of Waldorf. You can read more about the history of this area at: https://www.summitpost.org then search for Mount Wilcox under "Climbing, Hiking and Mountaineering."
The closest National Forest CG is further south on the Guanella Pass road. There are two: the Clear Lake and the Guanella Pass CG's. Otherwise, you can hope to get lucky and find a primitive site as you head up Leavenworth Creek. One of the best possibilities appears to be here: N 39° 38' 41.64" W 105° 45' 17.62".