This approach shares the same trailhead as the approach/trail to Weminuche Pass. At the trailhead kiosk, the trail to Squaw Pass #814 heads almost directly south. The trail is well-used and maintained at least as far as the turnoff for Squaw Lake. Beyond that point, it tends to become obscured in some marshy areas where tall grass overgrows the trail. From the kiosk where you may register your hike/climb, head south. The trail gains steeply the first half mile to where it drops briefly to cross to the east side of Squaw Creek on a sturdy bridge. From that point on, the trail will remain on the east side of the main creek. This is important to remember later on when the trail becomes more obscure.
After the crossing, the trail follows close to but well above the creek. The creek itself passes through a narrow gorge with some impressive cascades and deep pools. Eventually, after more than a mile, the trail enters the upper valley where things level out. From this point on, there is no more steep elevation gain - just a long slog of many miles heading generally south up the open valley. We last visited here in 2018. Before that, 2010. In 2010, the beetle-kill had consumed about 60% of the forest. By 2018, it had consumed perhaps as much as 90% for the full length of this valley. After about 2.25 miles, the Fern Creek trail comes in from the east. It is not easily identifiable. We saw no post or marker. In about 2 more miles, the 2001 Little Squaw Creek quad shows the "Fern Creek Cutoff" trail coming in from the east. We never spotted or noticed this and it does not show on the FSTopo 2016 map.
About 5 miles farther south on the never-ending trail is the turnoff for Squaw Lake. On our last visit, the most well-used trail took you down to the creek, crossed it and then began contouring uphill. The old bridge that was in this area, had been removed. Can't recall if a new one had been built to take it's place but a Google Earth photo from 2016 shows a bridge there at these coordinates: N 37° 38' 40.75" W 107° 14' 13.45". Elevation 10,430 ft. If you wish to continue to Squaw Pass, do not cross the creek here. Watch for a less distinct trail that will continue south on the east side of the creek. It will pass through a marshy area before getting back to drier terrain. If seven miles of backpacking is enough for you, then there is a good campsite if you go ahead and cross the stream, follow the trail briefly as it heads SW and begins gaining a little elevation. See coordinates below for this campsite. We will also mention that this Squaw Lake trail continues from this campsite for 2.6 miles with several major switchbacks up to Squaw Lake, with an elevation gain of 1,140 ft. In 2018, there was a very nice, grassy campsite on the east shore of the lake and south of the outlet. The trees here were all dead so it may not be a good place to stay if windy, but the low-growing grass is so nice, you can take off your shoes/boots and walk around barefoot. By now, we suspect that undergrowth vegetation is taking over. There's also some interesting large, old heavy equipment here.
Continuing on to Squaw Pass, it's another 4 miles. The 1973 Cimarrona Peak quad shows the trial on the west side of Squaw Creek. This is inaccurate. The trail remains on the east side all the way to the pass. At the following coordinates, the trail enters extensive willows and begins to gain elevation: N 37° 36' 45.67" W 107° 13' 00.55". 10,865 ft. The trail punches through fairly tall willows and then intersects the Continental Divide trail #813 at these coordinates: N 37° 36' 22.32" W 107° 12' 52.26". 11,190 ft. This trail intersection is where you can turn off to access Chief Mtn. via the CD trail. (Watch for moose in this area. On our last visit, we saw three bull moose feeding together in the willows.) For possible campsites and access to UN 13,010, continue south from this intersection to the vicinity of Squaw Pass where the combined CD/Squaw Creek trail heads west across some open terrain with lower willows and lots of wildflowers. Some possible campsites may be established in or near the trees on the west side of the pass. This is the terminus of this "approach."