We parked the motor home at Henrys Lake State Park west of West Yellowstone in the Island Park area for a week beginning Sept. 11. Heavy rain kept us from sight- seeing for the first two days. After the rainy weather began to lift in the afternoons, we took rides to Big Springs, the falls of the Henrys Branch of the Snake River and the site of the 1959 earthquake which caused a huge landslide forming a dam of the Madison River taking the lives of 28 campers. There are “must see” things outside Yellowstone NP.
Big Springs is an area about 1/4 mile long and about 20 – 30 yards wide in which water rises forming the headwater of Henrys Fork of the Snake River. The cabin and water wheel were built by Johnny Sack on land leased from the US Forest Service. His home and the furniture he built are now owned by the USFS and are on display to visitors in the summer.
This is the opposite end of the area of the springs, said to be one of the 40 largest natural springs in the world.
The daily outflow of water from Big Springs is over 120 million gallons at 52 degrees flowing down this channel.
Jo at the brink of the 114 ft. upper Mesa Falls of the Henrys Fork.
And there is a lower falls as well, viewable only from a distance.
EARTHQUAKE – LANDSLIDE AREA
40 million cubic yards of material slid from the side of this mountain down the the Madison River at the bottom of the canyon, and up the other side.
The large rocks center and left were at the bottom of he valley before the slide and were pushed this high on the opposite side.
View from the Visitors Center of the area from which the slide fell.
The Visitors Center displayed these drawings explaining the before and after of the earthquake – landslide.
Here is Quake Lake created from the Madison River by the landslide dam as modified by the Corps of Engineers. The view is from the Visitors Center which offers a lot of information about the earthquake and landslide.
https://en.wikipedia.org/wiki/1959_Hebgen_Lake_earthquake has more information.