The bridge at Page, AZ (Glen Canyon Dam / Lake Powell).  The tour guide at Hoover Dam commented on the last great runoff season (sometime in the later 80's) that they were concerned with the structure of the Glen Canyon dam.  It was not overbuilt like the Hoover Dam (estimated at 70% overbuilt) and some pieces of concrete came loose as the water raced over the spillway/s.  I don't know if the pieces were of the spillway itself or a part of the tunnel system.  The reflection by the right side of the bridge was from the window of the visitor center.

 

Looking out into Lake Powell.

 

East of Page, AZ.  AZ Hwy 98.

Just East of the AZ 98 / US 160 intersection.  "Watch for Animals - Next 100 Miles".  After the 4 Corners area we spotted a similar sign with a "157 miles" listing.

 

Near the 4 Corners area.

 

X marks the spot.