Chicago to Bend OR, alone: most scenic route?

[letsjumpnow]

Hi all!

I'm driving alone from Chicago to Portland/Bend OR between May 10 and 19. I've consulted Road Trip USA extensively, and the other posts here about Chi>portland, but haven't been able to map out a tight, realistic itinerary. I'm a photographer, so my primary aim is to get to the scenic places and take pictures. I have been down Hwy 1 on the pacific coast, but I haven't seen the west--none of the land between the ocean and Chicago! Forgive me, I'm only 23.

I've been advised to haul it on interstates through the Midwest more or less until I hit the Rockies, and then take my time on scenic and two-lane highways. I'm not sure whether to take a more northern route (first stop: Sioux City), go through the badlands, and detour all the way up to Missoula, or to stay pretty level (first stop: Omaha) and go through Colorado--on the US scenic highway map it's FILLED with stars!--and then straight up.

I suppose I'm looking for the best compromise between speed--in the blah parts--and scenic, in the scenic parts. Can anyone help me pull this together?

Thanks!

Alec