Yellow Knolls is located on the north side of Interstate 15, and is also in the south of the Beaver Dam Mountains Wilderness.

The knolls are located where the Virgin River enters Arizona from southwest Utah; the Virgin River is a due-southwest trending circuitous stretch, as it descends from higher elevations at the southwest of the Colorado Plateau, specifically the High Plateaus Section, a transition region to the lower elevation Great Basin that lies west, northwest; the lower elevation region is also at an intersection point with the northeast perimeter region of the Mojave Desert.

After a short stretch in Nevada, the Virgin River turns south in the Overton Arm of Lake Mead.

An aerial photo (shown above) shows the Virgin River meanders, and are easily identifiable on maps.

The section shows the Arizona-Utah border; the canyon coming from the south is Black Rock Canyon, arising from Mustang Knoll highpoint, 6,101 feet (1,860 m), a lower mountain section east of the Paiute Wilderness, located in the northeast end of the Virgin Mountains.