This is the American Canyon Trail.
Trailhead is at N38° 54.806' W120° 55.626'
This trail joins the historic Western States Trail (WST) for a short distance at about 3/4 miles from the trailhead.
Take a right at the first trail intersection and a left at the next intersection to stay on the American Canyon Trail.
Along the trail is the site of a historic gold rush town, once home to thousands of miners but now almost completely reclaimed by mother nature. If you look closely, you will spot a 30-foot high rock dam (1/4 mi. before cache), hidden behind a pile of tailings, which was built by hand during the gold rush.
The cache is about 1-3/4 miles from the trailhead at a small, semi-steep and unmarked side trail on the left (just before the Dead Truck Trail sign) that leads down to a very nice (and unusual) waterfall and a great pool where you can escape the heat on a hot summer day.
There are a couple of stream crossings along the main trail, but they should be fairly easy to get across.
If you continue on past the cache on the American Canyon Trail you will enjoy many more trailside waterfalls (mostly smaller) and a very cool slide.
Approximately 1-1/4 miles past the cache you will be at Main Bar Trail and the Middle Fork of the American River where there are primitive restrooms and a picnic table for a great place to enjoy lunch before the return trip.
This is an older kid, dog, and horse friendly trail. However the view of the pictured waterfall is not, and extra care should be taken when taking the small trail down and crossing the stream to view it.
There are many other accesses and loops that can be done to get to this cache too.
The cache is in an ammo can and contains the usual assortment of cache goodies.
You can go to ASRA Canyon Keepers and download a trail guide and map.