Pleasant 4.5 mile loop hike from the campground at Sugarloaf Ridge State Park in Sonoma. Head up Lower Bald Mountain Trail, hang a right onto Vista Trail and then return to the campground via Meadow Trail. The last part of the walk takes you past Saturn, Jupiter, Mars, Earth Venus and Mercury on the Robert Ferguson Observatory's Planet Walk. This spaces the planets proportionally distant from the observatory and if you took a right on Brushy Peaks Trail you can reach Uranus, Neptune and (don't tell anyone) Pluto, the prospect of which really makes me feel sorry for the New Horizons probe.
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