This is a pamphlet published by the Department of the Interior as part of the sesquicentennial of the Mormon Pioneers entering Salt Lake Valley. I must admit, I did not expect to find much in this pamphlet, and it only presented sites along the trail in Wyoming. Even so I was pleasantly surprised to find some amusing stories.
Simpson's Hollow in Western Wyoming is so named for Captain Lewis Simpson who was part of General Johnston's troops marching on Salt Lake City. The Mormon militia captured and burned 22 wagons of supplies at Simpson Hollow. This, and a couple of similar operations, along with the coming of snow, prompted General Johnston to winter around Fort Bridger. With another Winter of talk and negotiations, agreements were reached, and the "Utah War" for the mos part was diverted.
For some reason I hadn't realized the Mormons burned Fort Bridger as part of the same war. Subsequently the government occupied the fort.
As an auto guide this is useful. It gives general description of etiquette for following the trail.