If this is the image you are talking about:http://www.allposters.com/-sp/Road-Biking-in-Grand-Teton-National-Park-Wyoming-USA-Posters_i9565190_.htm
Then, yes, it is Grand Teton National Park.
The looming mountain is Teewinot - the Grand is behind it.
The stretch of road is the Park Road about 1 mile north of North Jenny Lake Junction.
I used to live in Jackson - still live in Wyoming 20 years after leaving Jackson.
The park is lovely, but there are quite a few people.
The photo was probably taken early on a late summer/early fall day.
There is a paved off-road trail from the Moose Entrance to Jenny Lake.
And there are a few places and times when the riding is nice.
(In spring after they plow the snow but the road isn't open yet is best.)
There is hiker/biker camping at Jenny Lake, but even the rangers don't often know about it.
Even though Jenny Lake Campground fills by noon - there are almost always hiker/biker spots.
There are lots of unpaved roads that you can ride in Grand Teton which offer all of the views -
But you have the feeling of solitude so rare on pavement.
PS - Pulled up Google Streetview of same location. CH clearly used telephoto.