North Dakota · National Park trail

Coal Vein Trail Post 16: Chimney

in North Dakota

What is unusual about the massive piece of clinker in front of you? Fires need oxygen, even when they are burning underground. As the coal fire burned deep into the hillside, cracks in the rock layers allowed air to be sucked down into the fire.

Fire burned up the cracks and baked the rocks nearby, forming vertical "chimneys." Chimneys are the hottest part of the coal fire and bake the rock inside into a very hard clinker called porcellanite which is especially resistant to erosion. This chimney you are looking at was exposed when softer sediments around it eroded away. There are many signs that large coal vein fires have burned throughout the park in the past.

Even today, coal fires can sometimes be found shaping and changing the landscape of the badlands. Geology is not only a study of the past; it is an ongoing process.

States: North Dakota
Trail type: National Park trail
Centroid coords: 46.9236°, -103.4025°

About Theodore Roosevelt National Park

National Park

This trail is inside Theodore Roosevelt National Park, a national park managed by the U.S. National Park Service. Conditions, road status, trail closures, and reservation requirements are published on the park's NPS page — check it before driving in, especially in winter or during major weather events.

Entrance fee: $30 per vehicle (verify current rate on the park page). An America the Beautiful annual pass ($80) covers entrance to all NPS units.

Official NPS trail page: https://www.nps.gov/places/coal-vein-trail-post-16-chimney.htm

Park homepage: https://www.nps.gov/thro/index.htm

Plan your hike

Practical notes

Maps + permits: long-distance trails like this often require permits for through-hiking, backcountry camping, or specific sections (especially in National Parks). Check with the maintaining organisation listed above and the relevant land manager before booking travel.

Water + supplies: water sources vary seasonally on most U.S. trails. Carry a filter and consult current trail-condition reports — through-hiker journals (PCT-L, AT Reddit, etc.) and the maintaining organisation publish regular updates.

When to go: hiking seasons vary widely with elevation, latitude, and snowpack. Through-hikers traditionally start the AT in March-April (Springer northbound) and the PCT in late April (Campo northbound). High-elevation western trails (CDT, JMT, Wonderland) generally aren't passable until July.

If you've hiked Coal Vein Trail Post 16: Chimney and have current notes (water sources, trail closures, permit changes), tell us at /contact — we update pages as we learn.