From US285 south of Buena Vista, take CR162 west past the Mt. Princeton Hot Springs Resort and all the way to the old town of St. Elmo. Take the road that exits CR162 and drive down into the town. Do not continue south on what becomes CR295. Drive into the main part of town an turn right on a main street that will cross the North Fork of Chalk Creek. Immediately after crossing the creek, make a left turn onto the Tincup Pass Road, #267. This road has a bad reputation, but most of that appears to belong to the upper reaches near the pass. We were last on it in 2017 and found the road to be rocky but manageable all the way to its valley terminus that accesses forest trail #1439. This is just past where the road begins to climb out of the valley for Tincup Pass. It will not be necessary to drive that far anyhow. So 4WD is not really required but good ground clearance will be an advantage. Most any SUV will do.
From the left turn after crossing the creek in St. Elmo, it's 3.2 miles to Woodchopper Creek. Shortly after crossing Woodchopper Creek, watch for a track turning off to the right and climbing uphill a little. This leads to a good camp area and a place to park for the day. There is no official trailhead here, and the vehicle track does not lead to the proper route up Woodchopper Creek.
On the drive in along CR162, there are five, National Forest Campgrounds; Boot Leg, Mount Princeton, Chalk Lake, Cascade and closer to St. Elmo, Iron City. St. Elmo is a popular weekend destination so expect these campgrounds to be full. Mt. Princeton CG, Cascade CG and and Chalk CG all have sites that can be reserved online. Iron City is first-come, first-serve. Bootleg is tent only and has no potable water.
Beyond St. Elmo on the Tincup Pass road, there are numerous primitive camp spots, including at the Woodchopper Creek and just a short distance past there. Most of the primitive sites are on the creek side of the road. Take your pick & good luck if it's a weekend.