The GRCO is open to the public on Friday and Saturday nights, weather permitting. The hours of operation will be from sunset to about two hours after nautical twilight. During the fall and spring these hours are approximately 7:00 PM to 10:00 PM. For winter months these hours are approximately 6:00 PM to 9:30PM and summertime hours will be approximately 7:30 PM to 10:00PM. Attendance is free, however a voluntary donation of $3.00 per person is suggested.
Private sessions are available by reservation through the Riparian Institute in one-hour time slots, beginning on the hour. A maximum of 20 people can be scheduled for any one session. These sessions will incur a fee of $5.00 per person, payable at the time of reservation. All fees will be refunded for events cancelled due to weather.