2gypsies beat me to it, but if you are coming in on I-80, turn north when entering Rawlins and take 287 to Lander, up through Dubois, over Togwotee and then down to the entrance to Grand Teton with Colter Bay about 10 miles from the entrance. Going up 191 does subject you to Jackson traffic and there is no way to get around it, all roads lead through Jackson in that area. And, the views going from Dubois up to the Park are great, especially when you round the curve right before Togwotee Mountain Lodge and see the Tetons. Right there is a turnout with a rest room and viewing area that offers a magnificent view of the Tetons, well worth the stop if you haven't seen them before. If you decide to go into Jackson one day, make reservations at the Bar J Chuckwagon for a great night of decent food and great western entertainment. They feed about 600 people in 20 minutes and then about two hours of western singing, not country-western, western and comedy. World class fiddle player and some really good singing. Something a person can take any age child to as the performance is totally acceptable to all ages.
