Best route Casper WY to Fishing Bridge RV Park

X2 to the Shonshoni route and up to Cody and on to Fishing Bridge.
but don't omit Grand Teton park from your trip. A good way to go home.

My preferred route from Casper is route 20 to Shoshoni, then route 26 over the Togwotee Pass to Moran Junction in Grand Teton National park, then route 191 to the south entrance of Yellowstone. Route 26 begins a gradual climb around Dubois to the pass then a gradual descent to Grand Teton. Route 191 begins a gradual climb after passing Jackson Lake, then descends to the south entrance station, then climbs again along the Lewis River Canyon to reach the plateau at Lewis Lake. From there it's just minor hills to West Thumb Junction, then pretty much level around the edge of the lake to Fishing Bridge. Nothing I would consider serious mountain driving on this route.

Spend some time in Grand Teton while you are in the area - it's our favorite place.

Take 20/26 west to Shoshoni and follow 20 north through the Wind River Canyon to Thermopolis. From there take 120 towards Cody and then take 14/16/20 through Cody and into Yellowstone. The roads are all well maintained 2 lane with no climbs of any real worry until you make the climb into Yellowstone. This is the East entrance and will take you directly to Fishing Bridge. The climb into YNP is a little steep and winding, but just take your time and you should have no problems.

This is the route we use.

Keith