Hidden Lake Trail is a 1.7 mile moderately trafficked out and back trail located near Forks of Salmon, CA that features a lake and is good for all skill levels. The trail offers a number of activity options and is accessible from June until October. Dogs are also able to use this trail.
Directions from Fort Jones: Follow Highway 3 south for 25 miles to the Callahan-Cecilville Road turnoff (Forest Service Hwy. 93/1C02). Continue on this paved, two-lane road for another 10 miles to Carter Meadows Summit Trailhead. From here, take the Pacific Crest Trail south for about 100 yards. Don't miss the sign at the junction directing you to the Hidden Lake Trail to the right.
Ditto to everything Kirtis wrote. Perfect for a quick trip with the kids. The campsite mentioned is really large and another was just to your left when you first get to the lake. Water wasn't as cold as expected ;-)
Short trail with well groomed trail. Trailhead begins right off the paved road. Trail gets steep for a bit towards the end. If you go in April expect to hike through some snow. West side of the lake has a very nice area to set up camp.