Sugarloaf Ridge State Park contains the headwaters of Sonoma Creek. It runs through gorge and canyon, across the meadow floor, beneath scenic rock outcroppings, and is surrounded at times by redwoods and ferns. A 25-foot waterfall flows after the winter rains. There is a self-guided nature trail along Sonoma Creek that starts near the picnic area.
Within the oak woodland and chaparral, the park has 25 miles of trails for hiking and horseback riding. Deer, gray foxes, the occasional bobcat and coyote can be seen in the park. In spring, wildflowers provide a colorful palette across the green hills. On a clear day, visitors can see views of the Sierra Nevada and the Golden Gate bridge from the 2729-foot summit of Bald Mountain.
The non-profit Valley of the Moon Observatory Association provides year-round astronomy education and interpretation programs at the Robert Ferguson Observatory within Sugarloaf Ridge State Park. Program fees vary, some are free with the payment of the park's Day Use Fee. There are three telescopes and the New Generation 40-inch Telescope Project at the Ferguson Observatory which will be one of the largest telescopes dedicated for public viewing.
