Stone Lagoon and Big Lagoon are about 35 miles north of Eureka, up where the "Elk Crossing" highway signs are meaningful, and just south of Redwood National Forest. A seriously scenic area. Both Big and Stone Lagoons are separated from the ocean by a very narrow sand beach, maybe 100 yards wide in some places. Both lagoons are fed by creeks, but are apparently subject to sea water incursion when big storms breach the sand spit. We chose Stone Lagoon for our paddle because it was a windy afternoon, and the launch area at Stone Lagoon would make us paddle out into the wind (at our back on return). Despite the hard wind, the water was warm. I saw a seal in the lagoon; not too far to cross the beach. This is a very pretty place, and would make for an enjoyable day-long paddle with picnic and swimming combined. At Big Lagoon, the feeder creek is said to be a worthy destination, where elk are frequently seen.
From the parking area by the launch spot, you can choose to either enjoy the beach, which is very scenic with lots of driftwood and big rock features nearby, or the lagoon. There is no fee at Stone Lagoon (there is a small fee at Big Lagoon, where they also have camping), and the parking area is a short distance off of Rt. 101. There is a visitor center on the highway, but it was closed the day we were there.