You can follow the road at the north end and ride across the dam but you have to get around or under a gate that blocks cars from the dam.
We like to ride the new trail in Laughlin NV upstream from the casinos to Davis dam. You can follow the road at the north end and ride across the dam but you have to get around or under a gate that blocks cars from the dam. On the other end of the dam there is another gate near the visitor center that is even more difficult to get around. If you can negotiate those two obstacles you can make a loop from Katherine landing road to the highway and across the bridge back to casino row.