Indiana to Mt. Rushmore

on i-90 you have the corn palace at mitchell,sd, wall drug, the bad lands, the minute man missle site and the black hills.

On I 80 as you enter Iowa stop at the biggest truck stop in the USA . Three floors to view . On the grounds there’s a antique truck museum and well worth stoping for. Free entry only donation if you show desire

I am going to offer an alternative route to the black hills. Go west on I-80 to Iowa City then north on 380 to Waterloo. Then take hiway 20 all across Iowa and Nebraska. It is 4 lane in Iowa and 2 lane in Nebraska. The Nebraska road is straight; level and pretty wide. Go west to Chadron then go north to the Black Hills. We have done this 3 times and much nicer road than the interstate. This way you see the sand hill area of Nebraska. Lots of City camping along 20 in most of the small towns. See the Black hills (lots of camping on the south end). Then if you want to just go home take 90 across SD, MN. We've done the Black hills numerous times in the last 40 years as used to live in N. Ill. Whatever you do, don't miss Crazy Horse in the hills.

From Elkhart you want to take I 80. Then I 39 N to I 90. If you go I 90 you go right through Chicago.
Lots to do around MT Rushmore, Black Hills, Don't miss Custer State Park. Wall drug for the kitch.