In case you want fishing you may always stop at Sierra FLY Guide, and from Shell Lake you get a good view of Gaylor Peak. This lake is so wonderful. Lakes? Sure, Fantail Lake is in the neighborhood, and don't leave Shell Lake without first going for a hike along the Gaylor Lakes Trail. So many fun things in the Central Sierra Nevada, just unbelievable. Hiking is a popular thing to do around Shell Lake; Pacific Crest Trail - section 12 is a perfect local trail.
Sawmill Campground is a splendid local campground; going for a horse ride at nearby Frontier Pack Train is always a fun thing to do.