Brumley Mountain
One of the most prominent landscape features visible when looking in this direction from the High Knob Tower is Brumley Mountain, a long, elevated ridge that runs roughly southwest to northeast on the far horizon. When viewed with binoculars from the Knob (see the photo with this placeholder as an example), Brumley Mountain stands out as especially stark against the surrounding countryside. On clear days, you might even be able to pick out the long, brick buildings at Castlewood High School in the valley between the Knob and Brumley's ridgeline.
Brumley Mountain really isn't a standalone mountain at all but is instead an offshoot of sorts from Clinch Mountain, a much longer ridge that runs across much of the southern view from the Knob (see the Clinch Mountain placeholder in this guide to learn more). Brumley Mountain itself runs just to the south of and above the Clinch Mountain ridgeline, at times rivaling High Knob in elevation by reaching over 4000 feet above sea level. It's this height and the sheer bulk of the mountain that makes it so dominant in the view from this spot at the tower.
Perhaps the most fascinating part of Brumley Mountain, though, is what you don't see from this vantage point on High Knob. Hidden from view in the low swag between Clinch Mountain's main ridge and Brumley Mountain is Hidden Valley Lake, a lake originally constructed as part of a hydroelectric project but now a popular recreational feature for fishermen, campers, hunters, and hikers. The flooding of Hidden Valley Lake covered up a unique cranberry bog that once occurred in this drainage at Brumley's base. Cranberry bogs like this one are actually remnants of ecosystems that once fluorished in Southwest Virginia at the peak of our most recent Ice Age but receded and moved north as temperatures warmed around 10,000 years ago. A new, 14-mile long hiking trail (aptly named the Brumley Mountain Trail) runs the length of the northern ridge of the Brumley Mountain complex to the Channels, another fascinating ecosystem which was carved from sandstone following millennia of freeze/thaw cycles by ice and snow. This repeated freezing and thawing has opened up deep passages - the "Channels" themselves - through sandstone atop Brumley Mountain, and the resulting Channels have become a popular recreation destination for those from here in Southwest Virginia and beyond.