Cow Hollow Road is a nice drive through the golden rolling hills of eastern Oregon. The tall grass surrounding you allows for great views of the surrounding terrain, such as Chalk Butte. This trail traverses through an open range, so beware of livestock on this dirt road. 4WD is not necessary, but make sure you have high clearance.
Near the trail's eastern section, as the terrain becomes more rugged, you'll start to lose sight of the tracks. Eventually, you'll come to a gate that you can open, but the tracks disappear. This is the end of the trail; although some mapping software shows the trail goes through, it does not.
The area has many other great trails to explore; this trail intersects with Twin Buttes and Shell Rock Road.