Overview
Popular South Mountain destination from multiple trailheads, view map. Attractions include the Wonder Rift, a natural tunnel and bridge nearby. Accessed via the National Trail at either end. Not mountain bike-friendly and may require the use of the hands in a couple of areas.
History
1934 SoMo Master Plan landscape architect William H. Douglas is credited with naming "Hidden Valley" and "Fatman's Misery". The proposal surfaced in an extended master plan in 1935.
Hike
From the west end you are immediately just above the Wonder Rift. A rift is a crack, split, or break in something. This narrow gap between boulders is popularly known as "Fat Man's Pass". Other names over the years include "Fat Man's Misery" and "Fat Man's Trap". This is a popular hiking destination, it is not uncommon to see people taking photos and playing on the boulders. Early morning light offers the best photogenic opportunities.
The park recognizes Hidden Valley in print and signage. Be grateful. Do not expect a clear path of travel. The unmaintained trail continues down the wash. More than one path exists. As long as you aren't ascending out of the wash more than, say, ten feet, they all get the job done. Keep an eye out for the five petroglyph sites along the trail. Unfortunately, two near the tunnel have been seriously vandalized.
0.2 mi - Hole obstacle. Go 5 to 10 feet up the left rock, through a low ceiling hole, and down slickrock on the flip side. Some will need to use their hands. On my first visit, I scooched my boot down the slickrock. If you go straight through following the wash, you will probably have to get on your stomach or back.
0.35 mi - Drop obstacle. You can slide down into the wash. This one is short but steep. A safer option is to stay right, and a use-trail will take you down in a more gentle fashion.
0.38 mi - Mushroom or spaceship rock. The turn for the natural bridge takes off east leading up and out of the wash. The park took the bridge off their maps and brochures decades ago. Hints of an old CCC trail are evident. It's more of a rock hop, from what I've heard... I waited while my camera went exploring since travel on unmaintained trails is not permitted.
0.42 mi - Natural Tunnel! Most walk through this fan favorite. Some get a little more adventurous.
When hiking several trails on a single "hike", log it with a generic name that describes the hike. Then link the trails traveled, check out the example.
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.