Tri-State Marker Trail (White Clay Creek State Park) Hiking Guide
The Tri-State Marker Trail is a hiking-only loop in White Clay Creek State Park, north of Newark, that leaves Delaware, climbs through wooded ravines in Pennsylvania and reaches the stone marking the point where Delaware, Pennsylvania and Maryland meet. Mason and Dixon called the spot the Northeast Corner of Maryland. It starts from the nature center parking area on Creek Road, roughly 17 miles and a half-hour drive from downtown Wilmington.
Permit: White Clay Creek State Park charges a daily vehicle entrance fee from March 1 to November 30: $5 for Delaware-registered vehicles, $10 for out-of-state vehicles. Walking or biking in is free. A Delaware State Parks annual pass ($50 Delaware plates, $100 out-of-state) covers it.
Distance and Climbing
Delaware State Parks lists the trail at 3.5 miles and rates it moderate, though the trail's own description calls it a 4-mile loop. Pennsylvania's DCNR, which manages the half of the loop inside White Clay Creek Preserve, also gives 3.5 miles and rates it more difficult. Hiking Project maps it as a 3.3-mile line with about 324 feet of climbing and grades that touch 20 percent; that climbing figure is the one used here. The hills are short and frequent rather than one long ascent.
The Corner Stone and the Arc Corner
The marker you reach is not the original Mason-Dixon double crownstone but an 1849 replica, with a brass 1935 U.S. Geodetic survey disk drilled into its top that officially designates the corner. Mason and Dixon surveyed this ground between 1764 and 1769. The loop also passes the Arc Corner Monument on the state line. Hiking Project's contributor describes smooth, well-built dirt tread with sturdy bridges at every stream crossing, and a pocket of pine woods tucked into the hardwoods.
Fees, Hours and Dogs
Driving in costs $5 a day with Delaware plates and $10 with any other state's, collected from March 1 through November 30; there is no charge from December through February, and anyone arriving on foot or by bike pays nothing year-round. Hours run from 8 a.m. until sunset, and leashed dogs (6-foot maximum) may come along. Bikes are not allowed on this trail, which keeps it quiet.
Hunting Days and Weekday Construction
White Clay Creek uses deer hunting to manage its herd. On the park's latest gun-season closure map, for 2025-26, the Tri-State Marker Trail was not one of the trails marked closed. For 2026-27, the gun weeks fall on November 13-21, December 12-19 and January 16-23, plus a youth shotgun hunt on Saturday, November 7, and Delaware allows no state park hunting on Sundays. Bright clothing makes sense on those days. Separately, the park posts that the PennDel Trail is closed for construction between Hopkins Road and Chambers Rock Road from 6 a.m. to 4 p.m. on weekdays, so expect detour signs near Creek Road during the week.
Hiking tips for Tri-State Marker Trail (White Clay Creek State Park)
- Park at the nature center lot on Creek Road, where the trail starts.
- Carry the park map; Pennsylvania's DCNR lists the trail as unblazed.
- Look for the brass 1935 survey disk on top of the marker.
- Plan a Sunday hike during November and December gun seasons if you want to avoid hunting days.
- Keep dogs on a 6-foot leash on both sides of the state line.
Nearby trails to explore
- Bryan's Field Trail (White Clay Creek State Park)
- Rocky Run Trail (Brandywine Creek State Park)
- Swamp Forest Trail (Lums Pond State Park)
Hike this trail with TrailMates
Three states in one hike makes the Tri-State Marker an easy sell to friends. Post the loop in TrailMates, agree on a start time at the nature center lot in the event's group chat, and walk to the corner stone together. Download TrailMates on the App Store or Google Play.