Trees are among the oldest living things in the world. They are more like us, it turns out, than we imagine. They suckle their young. They make good friends, moving their thickest, sun-blocking branches out of the way of their neighbors’ sunlight. Trees count the passing time and days, and collaborate by sending electrical signals across a fungal filament network that is sometimes referred to as the Wood Wide Web. While it’s not known why, they keep the stumps of fallen companions alive for hundreds of years by feeding them through grafted roots.

Trees, to put it plainly, are social beings. “Sometimes, pairs . . . are so interconnected at the roots that when one tree dies, the other dies, too,” Peter Wohlleben, a German forest ranger and author of The Hidden Life of Trees, told The New York Times. Some trees, of course, are also revered by human beings. In Maryland, the famous Wye Oak, which sprouted in the 1500s in the village of Wye Mills in Talbot County, was named the largest white oak in the country by American Forests magazine in 1940. Years earlier, in 1909, Maryland’s first state forester, Fred Besley, along with a descendant of one of the early Wye Oak property owners, had photographed and measured the great tree, which continued to attract visitors until its death nearly a century later. (It finally succumbed after a storm on June 6, 2002, by which time it had soared to nearly 100 feet in height, with a canopy that spread 119 feet. The main trunk of the mammoth beauty weighed more than 61,000 pounds.) Recognizing the importance of preserving other specimens, Besley started the Maryland Big Tree program in 1925—the first such effort of its kind in the U.S.—to highlight and preserve the state’s largest and oldest trees.

Associated with the state Department of Natural Resources today, the volunteer-led initiative documents more than 1,600 trees in its registry, including state and county champions culled from Maryland’s 250 native species. The formula used to measure trees includes their circumference, height, and average crown spread. “People send in applications for their trees to be listed nearly every day,” says program coordinator John Bennett, adding that beloved trees have come to feel like a part of the family through the years. “When we go to measure a tree, a lot of times the photo album comes out, too. There will be pictures when the kids were young next to the tree. Then, maybe a swing or picnic table underneath it a few years later. Wedding pictures. Photos of the dog and grandparents—all with the tree as part of the picture.” Baltimore City has almost 40 trees on the registry. They include publicly accessible trees at Druid Hill Park (check the English Oak state champ on the park’s west side), Cylburn Arboretum, and Leakin Park. Baltimore County has nearly 200 registered trees, including a former national champion 112-foot American Elm in Lutherville. (The Maryland Big Tree program website includes photos and directions to assist visitors.) One of Bennett’s favorite trees is the current state champion White Oak, which stands 96 feet tall on the property of the Calvert Brick Meeting House in Cecil County, not far from where he grew up. It’s said to be more than 400 years old. According to legend, William Penn climbed the tree in 1682 to survey property he claimed for Pennsylvania. The dispute over the land with a certain Lord Baltimore was later settled by a couple of guys named Mason and Dixon. “That’s the story, according to an old Cecil Whig reporter, who wrote about the tree years ago,” says Bennett. “He’d heard that story from his grandfather, I think. Naturally, that tree would’ve been a lot smaller back then,” he adds, with a chuckle. “I’m pretty sure there would’ve been some other trees around at that time that would’ve better suited Mr. Penn’s purposes.”

In the end, whether the William Penn story is a tall tale or not probably isn’t that important. Maybe what matters is that the yarn continues to be passed down from generation to generation. The bond that people form with their favorite trees is often not just familial, but spiritual.

“Sitting in the shade of a big tree, listening to its leaves rustle, it’s like sitting alongside a river running,” Bennett says. “It connects to something primordial in us. It quietly reminds us that we are part of something larger than ourselves in this world.”