re: Bob Marshall Wilderness or Black Hills/Badlands NP...where should I backpack?

Chicken
You’ve received lots of recommendations I’ll add my two cents. I lived in Billings for eight years and as someone mentioned, you can’t go wrong in the Mountain West. There are so many options, for me there are two deciding factors:
1. GRIZ – I have an irrational fear of being part of the food chain. The stories I read about hikers and hunters made me plan my excursions where the GRIZ weren’t supposed to be. With that being said, I loved the Crazies – give me Jeremiah Johnson, the Judith, and the Musselshell. A spectacular mountain range.
2. Plan your trip to catch the Aspen turning. With their bright yellow leaves, crystal blue skies and all the meadow grasses against the evergreens, I miss the west so – Sun rises are awe inspiring in high country.

Aspen turning and high country Montana equals the possibility of snow and the elk will be squealing. Two of the eight years I bow hunted the high country I experienced heavy snow – If you are going to the Bob – be aware that the wilderness can be unforgiving when mother nature flexes her muscle.