I've spent a bit of of time riding in NE, SD and WY, and I strongly agree with everything Sleddog is saying.
The Red Lodge Cafe in Red Lodge is Frump recommended and its also where the locals eat.
I like taking BIA 2 from Buffalo Gap, SD through Pine Ridge Res. to Hwy 44 through Wood, then down to 18 near Winner. Dropping from there down through Spenser, NE then take Outlaw Highway (12) through Niobrara, NE to Sioux City. Much of BIA 2 is not paved but its a big road. I too am a big fan of 44 but YMMV - its not for everyone. Wife and I have had a lot of adventures on that stretch and it only takes an hour or two more then I-90. Make sure to slow down for the small towns ($$).
Also, going out you can run kitty corner across Nebraska from Sioux City through Ord, NE and see some of the Sand Hills. It saves about 50 miles, a gallon or two of gas, and it won't take you any longer then I-80. I'm not a big fan of I-80 in eastern half of Nebraska.
Posted on Mar 6, 2012, 1:48 PM from IP address 188.8.131.52