Yay, Brownlee Road
After getting back on NE2 head West to Merriman, NE. Go North on 73 to Martin, SD. Go West on SD18 to Cr-10, follow Cr-10 it will turn into BIA-2 & go through Potato Creek on Big Foot road. It will intersect with SD-44. Take 44 to Interior, SD. There is an entrance to the National Badlands park there.
There is primitive camping (A few shelters & picnic tables are available) at Sage Creek Campground in the North West corner of the Park. The Sunrises & Sunsets are worth seeing!