Grounds daily 24 hours. Visitor center and ranch buildings open daily 8:30-4:30, May-Oct.; 9-4:30, rest of year. Buildings daily 8:30-4:30, Mar.-Oct.; Mon.-Sat. 9-4:30, rest of year. Buildings closed most major holidays. House tours are offered based on staff availability. Bus tours depart Sat.-Sun. at 11 and 1, late Apr.-late Oct.; other times based on staff availability. Closed major holidays.