The January 1997 flood of the Merced River ( flooded/flooded from the watershed/floodplain of the Merced River ) occurred from December 31 , 1996 , to January 5 , 1997 , throughout the Yosemite Valley in Yosemite National Park , Mariposa County , California , US . The flood stands as arguably the park 's worst natural disaster to date ( some would give this designation to the rockfall of 1996 or the Rim Fire of 2013 ) , and inarguably the worst flood in park history . The Merced River at Happy Isles peaked at 10,100 cubic feet per second during the flood . A book was written on the flood later in 1997 by Mark Goodin titled '' Yosemite : The 100-Year Flood ''
Rim Fire of 2013
Rim Fire
1997 Merced River flood