EDIT 12/2019: The route described in this comment is no longer open. At the time I ran this, the best information I had was that the Park County segments of FS 220 were considered open. Those have since either been re-closed, or were never actually open in the first place. Only the portions of FS 220 in Teller County are currently open, though this may change with the completion of the PSI travel management plan in 2020.
This past Saturday, a friend and I ran the lesser known loop from the main Hackett Gulch trail southeast from the Platte River back up to the junction with Sportsman 897 and FS202, before taking FS202 back out to Cedar Mountain Road. Known variously as the South Hackett route or Old Stage (and sometimes also called Widow Maker, though that name properly refers to a long-closed trail on the west side of the river), this section of trail is actually open, though some sources mistakenly list it as closed.
Before running it, I confirmed with Jerry at Predator 4WD that this trail is indeed open, and also found that the Mile High Jeep Club ran it as an official trail run in September of 2017. We also found the Forest Service gate at the intersection with FS897 and FS202 open.
According to Jerry, "The Forest Service accidentally opened that section of trail a few years ago. It was called Old Stage for years and before the Hayman fire was marked FS220A. Sometime after the Hayman it ended up as FS220 which is the number for Hackett. It is now on the Federal Registry as FS220 which is open."
This section of trail starts out on the east side of the Platte River about 100 feet south of where the south fork of the main Hackett trail reaches the river. It climbs up a steep, rutted hill that can be easy to miss in the trees. We did see some "closed to motor vehicles" signs nearby, but since I confirmed the trail is indeed open, I think they were talking about some other areas nearby, and not the trail itself. This hill, for which some sources have re-purposed the old name "Widow Maker Hill", has a very difficult line to the right in a deep trench filled with loose gravel and large rocks, and an easier bypass to the left. We took the bypass, which required hugging the left side and being careful not to slide down into the trench on the right, risking a rollover.
Past this hill, the trail climbs steeply upwards until it reaches a rock obstacle just below the crest of the hill, which requires negotiating a V-shaped notch between two large boulders. After that, the trail continues for a couple miles through a burn area, winding around several hillsides and crossing a series of gullies. Right after you cross a gully with a very sharp left turn, the trail crests a rise and then enters another gully with a series of rock obstacles. These are not very difficult, but can be fairly tight. The trail continues up that gully for a ways, before emerging in a forest of short aspen trees (beware of lots of overhanging branches with high potential for Colorado pin-striping). It continues up the valley through that forest, until coming out into a series of open meadows and sparse pine trees, where there is a Forest Service gate at the junction with FS897 and FS202.
Turn left to take FS897, and right to take FS202. Both lead back up to Cedar Mountain Road (FS360). FS202 is the more challenging route with a couple steep rocky hill climbs, and that is the route we took. The portion of trail from the FS220 gate and the last waypoint listed on TrailsOffroad for FS202 was clear and had nothing of interest to note. You could easily run FS202 and FS897 as their own loop.
Overall, this was a fantastic and fun trail with a number of more challenging obstacles than you will find on the main Hackett trail. If you want to run this, do it soon, because this route could very well end up being closed in the ongoing PSI Travel Management process.