Pretty much any state east of the Mississippi that year experienced a tremendous amount of rain. Meanwhile, the western US was in a severe 100 year drought. One of the side effects was heavy river, waterfall and stream flows.
Decades back, a dam was built just up the river from this location. Interestingly, these falls did not exist until the dam filled and created these amazing and unanticipated falls out of nowhere! It seems that the land had many caverns and cracks that filled up with water, and the dam now keeps them flowing.
By the time I found a good spot to set up my camera, the morning sun was bright, causing bad waterfall picture conditions. With a little luck, a big storm rolled in covering the falls in shadow and rain so that I could grab some long low light exposures (then hide under a rock). By the time the sun streamed back out, I was able to shoot fast bright light exposures that featured the passing birds. “Grandeur” is another great fusion image that combines not so much time together, but exposure speeds to achieve the final dream-like effect.