The Potomac Valley Audubon Society invites members and friends to come to Fort Frederick State Park in Big Pool, Maryland, on Saturday, Oct. 25 for a late afternoon guided tour and an evening astronomy program.

These are family friendly events, and children will be welcome. Both events are free but the park charges an entrance fee of $3 per car for Maryland vehicles and $5 for out-of-state vehicles.

The guided tour of the park will begin at 5 p.m. It will be led by the Park’s Naturalist, Charles Sullivan.

The astronomy program will last from 7 to 9 p.m. If weather permits, it will be held outdoors with participants using the park’s 10-inch Dobsonian reflecting telescope to learn the basics of sky navigation and telescope use. In that case, participants should dress warmly and bring a lawn chair, flashlight, and, if desired, a blanket, snacks and warm drinks.

In the event of clouds or rain, an indoor astronomy program will be offered.

Fort Frederick State Park is about 18 miles west of Hagerstown off I-70.

Pre-registration for these events is strongly encouraged but not required. Easy registration and more information, including detailed directions, are available on the Potomac Valley Audubon Society’s website at www.potomacaudubon.org.