📜 Blueschist rocks in Sonoma County, California, with smooth, shiny patches. 🔍 Scientists believe these were used as scratching posts by Columbian mammoths. Patches are 10-14 feet above ground, consistent with mammoth shoulder height. # Why Go 🐘 Witness evidence of prehistoric megafauna 🧗 Popular with climbers for jagged sides 🚶 Explore Kortum Trail to the rocks 🏞️ Enjoy a vast prairie landscape # Getting There 🗺️ Search Google Maps for 'Sunset Boulders'. 🚗 Turn west from Route 1 onto Goat Rock Road; look for pull-offs. 🚶‍♂️ Follow Kortum Trail from pull-offs to the rocks.