Below is an evolving map of the New Jerusalem area. I believe it’s reasonably faithful to the 1865 time period. You’ll have to download the pdf for the detail – link below the map.
One or two things to note…
1/ Settlements are in blue – it doesn’t include every single one but the majority are included and it gives a pretty good idea which areas have been settled.
2/ Forts are in red – not all of these are military – in fact the majority are stockades. Fort Laramie is the main military presence in the area.
3/ The circles eminating out from New Jerusalem are to give an idea of travel times. Each circle is 50 miles, which I believe is about a day’s travel by horse or stagecoach. Research leads me to believe that if you have a fast horse or can change horses and you’re really pushing it you could possibly double this. A march on foot would be about 25 miles i.e. a ring of the circle every 2 days, and wagon trains travel at about 15 miles a day i.e. a ring of the circle every 3 days. If you’re estimating how far someone can get remember to take into account obstacles such as mountain ranges etc. The circles only indicate travel distance as the crow flies.
4/ The red line is approximately where the Oregon Trail was and the yellow line is the Bozeman Trail. There was also a second route, the Bridger Trail, paralleling the Bozeman Trail south of the Big Horn Mountains. This was a safer route than the Bozeman Trail, which was prone to Indian attack as it ran smack through their prime hunting grounds.
5/ There’s also a general indication of where the Native tribes were at the time. The main action being the Teton/Lakota Sioux pushing west displacing the Crow from the hunting grounds.
Hope this is useful.