It runs through a narrow canyon cut into ancient lava flows in southwestern Idaho.
In the basins below volcanic peaks ancient lava flows could tell of the planet's more dynamic past.
Within another quarter glass, the ancient lava on the peaks had given way to sandstone alone, and more ever greens were evident.
Even he ancient lava flows seemed to ripple, liquid once again.
Staggering in the blasts, he climbed onto a low swell of the ancient lava and looked upslope.
For several miles below the oxbow, the current ran smooth between fifty-foot cliffs channeled from the ancient lava.
They are now known to be vast solidified pools of ancient basaltic lava.
Black Ridge was a wide ledge set atop a dark outcropping of ancient lava.
The ground was complex now, covered by many ancient lava flows: this Mountain had spewed out liquid rock over and over.