Art Clark has been exploring the Sierra for decades. He skis and hikes the Sierra looking for old ski trails and interesting sights. In Summers he's taken to searching for the sites photographers in the old days photographed and making his own pictures showing the changes over time, like the one here. The he carefully runs the two versions, then and now, through his software to make an animation.

Here we have two views of the Lincoln Highway right at Donner Summit and just down from the Pacfic Crest trailhead going south. The left view was taken in the 1910's(note the car in the lower left) and the right view in 2011.
Click on any of the links the table below to see Art's Then and Now's and then click at the bottom as they open up to see the animation as yesterday morphs into today.. Almost all of them are from photogrphs taken to document the building of the Central Pacfic Railroad by Carleton Watkins or Alfred A. Hart in about 1867.