Waterville Bridge, Appalachian Trail

Three miles (5km) of downhill hiking from High Rock brought me to the Mason-Dixon Line marker, an 18th-century boundary that once divided the North and South. At this marker, I crossed into Pennsylvania, state number seven and the start of the northern section of the AT.

The path wound through dense woods and rolling hills, with sunlight filtering through the leaves above. After a short break at Deer Lick Shelter, I continued moving through the quiet, shaded forest. This area has seen its share of history, from the Civil War to ironworks that once thrived here, but now, it's all about the stillness of nature. The only sounds were my footsteps and the occasional chirp of birds, a perfect contrast to the weight of the past.

As I climbed up to Chimney Rocks, I entered Michaux State Forest. This area was once central to Pennsylvania's iron industry. Charcoal hearths are still scattered throughout the woods. The forest was named after botanist André Michaux, who was sent by France's King Louis XVI to study North American plants and collect species that could be useful back home. He travelled widely and explored the Appalachian region, documenting hundreds of plants, many previously unknown to European science. His work shaped botanical knowledge, leaving a legacy on both sides of the Atlantic.

Descending into Caledonia State Park, I came across traces of its ironworking past, hidden among the old foundations scattered across the landscape. This was once the site of an iron furnace owned by Thaddeus Stevens, a Vermont native who began operations here in 1837. A U.S. Congressman, Stevens played a key role in shaping Pennsylvania's public school system. During the Civil War, the furnace was destroyed, and the nearby fields were used as makeshift hospitals during the Battle of Gettysburg. Though the furnace was rebuilt after the war, it eventually closed in 1902, and a year later, the land was transformed into a state park. 

As I pressed on, I reached Boiling Springs, home to one of the AT Conservancy's regional offices and the only one located directly on the trail. I took advantage of the shower facilities and collected my resupply box, a treat after miles on the trail. Boiling Springs may feel like a hiker town today, but in the 1800s, it was a vital stop on the Underground Railroad. Daniel Kaufman, who laid out the village, sheltered people escaping enslavement in his barn and nearby woods, helping them on their journey to freedom.

I crossed the Susquehanna River through Duncannon and began the steep ascent to Peter's Mountain, an elevation gain of about 800ft (243m). At the top, the mountain ridge stretched before me in a near-straight line for the next 15mi (24km). The trail was quiet, with only the sounds of the wind through the trees. Lost in thought, I would occasionally surface to the present with the rustling of an animal in the underbrush. 

I descended into Green Point and soon reached the Waterville Bridge, an iron masterpiece crossing the Susquehanna River. Constructed in 1889 and moved to this location in 1993, the bridge's lenticular truss design was a stunning example of 19th-century engineering. Originally a road bridge, it was repurposed for AT hikers when it became too narrow for vehicles. As I crossed, I took a moment to watch the river flowing beneath my feet, reflecting on the Susquehannock people who once inhabited these lands long before European settlers arrived.