The second half of our tour of Theodore Roosevelt National Park South Unit’s loop road comprised two short nature hikes: Coal Vein Trail and Ridgeline Nature Trail. Throughout the park, we found the interpretive brochures consistently well-stocked, well-written, and informative. Kudos to the park staff and volunteers. Sean delighted in reading the brochures aloud in his radio voice.

The sky had grown insistently moody by the time we reached the parking lot for Coal Vein Trail, a 0.8-mile loop in the western part of the South Unit. It was here that a coal vein slowly burned for twenty-six years (1951-1977). While it has been out slightly longer than I have been alive, the evidence is captured in the rock, and the vein is clearly visible at points along the trail.

The gray layers are bentonite deposited from the ash of the Rocky Mountains as they were forming (as in Badlands National Park). Bentonite is clay and is extremely loose. When it is wet it becomes impossibly slick and sticky and has been known since Roosevelt’s time as “gumbo.”

The trail left the most obviously visible parts of the coal vein and climbed up a short ridge among aged junipers. Some, in their tree form, were ornately twisted.

The trail descended and ascended affording alternating views of grasslands and juniper woodlands. We passed a few other people on the trail on this graying afternoon. Most were couples of retirement age carefully navigating the points where the trail crossed over gray bentonite and got slick or particularly muddy from the rain the day before.

When the sky cleared for a few moments, the sun reflected off of the still-drying bentonite on the ridges across from us.

We saw no wildlife save birds on the trail, but we saw lots of fresh tracks, including bison, deer, and shod horses.

The juniper thickets tended to be found on the north-facing, protected slopes away from the beating sun. Although it was a cool 45 degrees, only a few weeks previously, in August, the temperature had approached 100.

The brick-red rock is heated clay formed by the burning of coal veins. It is known locally as scoria, but is really clinker. Which seemed odd to us, and we were amused every time we read that the proper name was “clinker.” According to the interpretive literature, true scoria is a volcanic ash, but there was no volcanic activity in the Badlands, only the ash that settled from the volcanoes furthur west. Regardless, it’s striking and adds great depth to the landscape’s palette.

The image above jolted me when I was going through iPhoto pulling images for this post because it is so obviously a log of petrified wood. But there in the moment standing in front of it, I didn’t recognize it as such. I knew there was petrified wood in the park. In fact, our intention was to hike to the petrified forest in the western part of the South Unit that afternoon. But there it is, right there in this image.

Near the end of the trail, we came across an arresting clinker formation. A little side trail led down the slope to it, and we went and had a closer look.

The mechanics of its formation were obvious. The once-gray clay had hardened and slightly shrunk as it was burnt dry, turning red and sticking together in the process. The innumerable crannies of this now-hard rock afforded tiny crevices where vegetation took hold, in addition to the lichens that painted the surfaces.

Sean provides scale in the image below.

After Coal Vein Trail, the loop road led us west and rose into the higher bluffs in the southern section of the unit. We stopped at a few overlooks to take in the views before we reached the parking area for Ridgeline Nature Trail.

At the parking area, we noticed a small SUV with Montana plates and a Montana Public Radio bumper sticker. We encountered the owners a short distance up the trail as they made their way down. They were a handsome, energetic retired couple. He was wearing a “Trout Unlimited” baseball cap. I remarked to Sean that they were my kind of folks with their public radio bumper sticker and swag from a conservation organization.

The 0.6-mile trail, which also boasted a well-stocked kiosk of interpretive pamphlets, rose steeply in switchbacks through juniper thicket up to its namesake ridge.

The ridge was vegetated in restored mixed-to-short grass prairie, more arid and shorter than the tallgrass prairie of Illinois.

The breezy ridge was dizzyingly fragrant, wild and familiar at the same time. The entire park boasted this fragrance to some extent, and now thanks to our interpretive brochure, we discovered its source: silver sage.

We were enchanted, and ran our hands along the leaves and branches, perfuming ourselves. We fell instantly in love with silver sage, one of the several species of sagebrush that blankets the West. It was the first time we were both truly, achingly tempted to take something from a National Park. We longed to cut some boughs to carry the scent with us.

But we didn’t.

Now that we knew what it was, however, we saw it everywhere. (It populates the first image of this post, but we didn’t know what we were looking at when I snapped that photo.)

This section of the park was still recovering from a human-caused wildfire, evidenced on the junipers in particular.

The trail descended steeply from the ridge and into the juniper woodlands of the north-facing slope.

As the trail rose again and led us back toward the Jeep, Sean spotted a lone bull bison in the distance. He captured the image below with his iPhone by taking it through his binoculars.

We returned to the loop road as it led us back toward our starting point at Cottonwood Campground. Along the way we spotted wild turkeys and feral horses. We were both getting hungry, so it was time to head into Medora for lunch.