The Potomac Valley Audubon Society is sponsoring a birding trip to the Altona Marsh west of Charles Town on Wednesday, July 27.

The trip is free and anyone with an interest is welcome to come along.

The trip will begin at 6:30 a.m. and will require pre-registration. To preregister and arrange a meeting place contact trip leader Sandy Sagalkin at 240-291-6465 or mon sansagalkin@myactv.net.

Altona Marsh is a 70-acre marl wetland. One of the few such wetlands left in the area, it contains a rare ecosystem and is protected by a Nature Conservancy easement.

This trip will involve about two miles of level walking, but some of the route will be along a railroad track.

Participants should plan to wear comfortable walking or hiking boots and bring along bug spray, water and, as necessary, a hat, sunscreen or rain gear. Binoculars will be available for those who do not own any.

In case of inclement weather, contact the trip leader to see if the trip is still on.

Various details of the trip could change depending on weather and recent bird sightings.