I saw a lot of unusual things this past week in Montana but this sight along the Missouri River at sunset (the timing of said sunset, also being unusual at 10 p.m.) won the prize.
Riprap, as rip rap, rip-rap, shot rock, rock armor or rubble, is rock or other material used to armor shorelines, stream beds, bridge abutments, pilings and other shoreline structures against scour and water or ice erosion. It is made from a variety of rock types, commonly granite or limestone, and occasionally concrete rubble from building and paving demolition. It can be used on any waterway or water containment where there is potential for water erosion.
pauses&clicks 