Our plan today was to drive around Custer State Park and we did part of the loop, it was interesting and beautiful, but the roads were very twisty  and if you have seen 1 buffalo you have seen them all. The bridge below is made of wood and as you can see it looks laminated.

The signs prior to us entering the park were very specific on the height and width that could go under some of the bridges and through the tunnels.

This bridge looked like it was made out extra large utility poles.

These are are several tunnels that were bored through the rock, it was only for
1 way traffic and we needed to honk prior to entering

Among the  towns people,  this was a must see  and take a picture  moment as well as the pictures below.

                                  

This big guy was just walking along the highway

He had the right of way, we just hung back until he was across the road.

The pictures below were taken in the cave and they do not do the cave justice. It was an amazing
 experience for both of us , we were fortunate to have a park ranger to ourselves to do the tour.
 It is a tour that we highly recommend. It is strenuous, but well worth it.