Armstrong Redwoods State Natural Reserve preserves 805 acres of old-growth coast redwoods in a temperate rainforest north of Guerneville, where heavy winter rains and summer fog help sustain the grove. Its notable trees include the Parson Jones Tree, the tallest in the grove, the ancient Colonel Armstrong Tree, and the burl-covered Icicle Tree. Preservation began in the 1870s when Colonel James Armstrong set the land aside, and after his death his daughter and the Le Baron family led a successful campaign to save it. Sonoma County bought the property in 1917, and it later became a state park and then a natural reserve focused on ecological protection.