Contact Us Contact Us The R3 Hotel is an adult resort, and you must be 21 or older to enter, except in our restaurant, during restaurant hours only. 16390 4th StreetPO Box 450Guerneville CA 95446. Phone: (707) 869-8399Email: info@ther3hotel.com Hotel Office Hours: Sunday-Thursday 10 am to 5 pm, Friday-Saturday 10 am to 7 pm