I agree, when I went to Sturgis in 2011, this is one of the places that I went to, I thought it was well worth it.

 

If you go in June or September you can see it from the top and that is amazing.

 

Great advice here. Get the map. You can easily run every road in the hills in 4 days (5 with Devil's Tower). You can probably do it in less time, but you'll miss some of the favorite stops.

My three favorite roads... and I'll run them multiple times are Iron Mountain Road, Spearfish Canyon and the Vanocker Canyon.
~If you can get on Iron Mountain Rd by about 8:30 am... you'll have it to yourself. That is a huge treat if you like to run a road hard.
~Vanocker Canyon is usually pretty light traffic
~Spearfish is hit and miss. We usually sit at Cheyenne crossing and time our departure to miss large trucks and slow cars. Sometimes it works...

A couple of suggestions:
385 is the "main drag" running North/South through the hills.
Alternate route from the south is-
East on 44 to Johnson Siding
Left onto Norris peak rd at Johnson Siding
Left onto Nemo Rd
Right onto Vanocker Canyon and it runs you into Sturgis... and from there you can take Boulder Canyon back down to Deadwood.
If you take this route make sure and stop in at Big Mama's in Nemo (if the gate's open, they're open). Also keep your eye's open on Norris peak road.. there's a house that has a huge iron Harley Davidson chair sculpture in the front yard.

Food (not a lot of fine dining in the hills)
Sugar Shack
Steak tips at the Loud American in Sturgis
Wolf Camp (Iron Mountain Rd) - Indian tacos
Sage Creek Grill in Custer (this is a bit more upscale and hipster.. excellent food)
Maria's Mexican in Custer (red food truck next to the VFW... Ah...mazing tamales)
Cheyenne Crossing (breakfast) - at the south end of Spearfish Canyon

Fun side runs:
North Rochford Rd - you'll have to go in and out from alt14 cuz' the pavement ends in Rochford. In Rochford, stop at the Moonshine Gulch. Very cool little historic bar. Road pavement is new for the last stretch into Rochford.

Silver City Rd (off of 385) - another in and out. Nothing much at the end but a little neighborhood, but the road is technically difficult.. so it's a fun challenge. Watch for sand.

Hill City/Keystone Rd - short cut between the two towns of Hill City and Keystone. Watch for the tourist train... no signals at the crossings. Fun road, very light traffic.

Wildlife Loop in Custer State Park.

Run 244 from East to West. There's a pull out on the right to stop and look at the faces and take a picture. Then after you pass Mt. Rushmore a small parking lot to pull in that's directly under the side of George Washinton's face.

 

Thanks for all the suggestions! Keep them coming.

 

go on to Rochford when ya get on that silver city rd---ya won't forget it

 

Very good suggestions in this post. Oh, and watch for deer.

 

Lovemychaos has it all down.

You can pretty much do the entire system in 4ish days. Enjoy

Dont forget to stop at Buckhorn Bar just west of Trailshead. Nice road west from Cheyenne Crossing to New Castle