Bring your swimsuit
This was a two day backpacking trip into Hidden Valley as described by Jack Carlson as Trip 14 in Hiker's Guide to the Superstition Wilderness.
The hike starts at the Peralta trailhead and takes the Bluff Springs trail to near it's end at the Dutchman's trail. It then climbs the SE corner of Bluff Spring Mountain on the Ely Anderson trail and then drops down into Hidden Valley. We didn't complete the loop that Carlson describes but did visit the East, West, and North-West overlooks of Bluff Springs Mountain. Our hike was 17.2 miles with an accumulated gain of 4116 feet. Both numbers are slightly higher than the loop that Carlson describes due to the back and forth nature of our exploratory trips from camp.
The drop into the valley from the Ely Anderson trail does not go through point FF on Carlson's Map 5. Point FF is at the edge of a cliff and there is a cairned route (but no path) that cuts NW 300 feet in elevation below the cliff. The cairns end with a large one 1000 feet NW of point FF. From that point it's a light bushwhack due north down to the creek. It's possible to avoid most of the catclaw by heading from one area of solid rock to the next.
There are two camping areas at the south end of the valley. The first one is 500 feet north of point PP on the east side of the wash. The metal chair described by Carlson is still there. This area is flat, open and uninteresting. It's advantage is that is located near the path to both the eastern and western overlooks. The second camping area is another 500 feet north on the west bank--just south of where Bluff Spring Mountain spring is shown on maps. This area is more interesting because the canyon walls are closer and the bushes are somewhat larger. We camped at this second spot. Considering how infrequently Hidden Valley is visited, there's a surprising amount of trash at the camping area and elsewhere: freeze dried food bags, old tin cans, beer cans, water jugs, etc.
My first trip from camp was up to the West overlook following Carlson's route. There's a good view across to Weaver's Needle. I think I got too high on the slope of the 3999 peak trying to avoid the area that Carlson warns is "loose and the footing is not good" and turned back. Shortly after turning back I found a cairn at: N33.44402 W111.35827. This cairn is the end point on the posted GPS track. There's some knee-high catclaw on the lower slopes but most of it can be avoided.
The next trip from camp was up to the East overlook (Carlson's point QQ). The GPS route shown is the route I used on the return trip. It's on the south side of the drainage while Carlson's route seemed to be up the north side. I couldn't find a good route through the catclaw on the north side. There are fantastic views down and east from this overlook.
The next trip from camp was north along the creek and then west to near Carlson's point RR. I could find no sign of Bluff Spring Mountain Spring--although the vegetation is heavier in this area. Carlson describes portions of this segment as some of the "roughest cross-country trekking in the Wilderness". It wasn't that bad although there were spots on the NW segment with pickup-truck sized boulders that took some scouting to find the easiest way over or around. There's knee high catclaw but little I'd call a thicket that can't be avoided. (I wouldn't want to try this segment with a heavy pack.) The first 500 feet headed north from camp we generally stayed in the creek bed. From there to the turn west we generally stayed east of the creek near the cliffs. There were several nice camp sites just south of the turn. Once we turned NW we ran into larger boulders. Sometimes we climbed over and through the boulders and sometimes we were just off to either side. Most often we seemed to be on the north side. About a thousand feet SE of Carlson's point RR we were surprised to find two areas with cattails and water in rock basins. It hadn't rained in months except for a quarter inch the week before. The cattails seem to indicate at least enough water year round to keep the soil moist.
We turned around near the NW overlook, broke camp and headed home
WARNING! Hiking and outdoor related sports can be dangerous. Be responsible and prepare for the trip. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water. Never go alone. Make an itinerary with your plan(s), route(s), destination(s) and expected return time. Give your itinerary to trusted family and/or friends.