Thanks, Bill.
A couple of questions.
1) The entire length of Sage Creek is 4" gravel or only sections?
2) Sage Creek Road ends in a canyon or is that the sheep road you're talking about?
I am hoping to use this road to travel south.
here's the planned start of my route:
https://goo.gl/maps/ShXqLEyuK152
Don't take Mike's advice. He's insane and has no real world understanding of how fast you're supposed to be able to travel on gravel roads.

Both times I've been there, it's been mostly gravelly hard pack w/ some slippy sections mostly where you'd expect them on a gravel road. It's insanely wide for most of it though. It's in the turns that the gravel can pack up a bit and not always where you'd expect it. It's very easy riding, don't get me wrong. Just be aware that it suffers the same fate as most gravel roads just on a much grander scale. And when you've been trotting along at 60 OMGs , I mean MPH, you'll think you've slowed way down for the turn. You might be right.

Just a bit south of Scenic on whatever that road is, (Bombing Range Road later turns into Bigfoot Trail) Sheep Mountain Road will be on the right. 43.724496, -102.528646 It's just a quick out and back but it's kind of spectacular and will scratch your offroad itch a bit more than sage creek did. However, if you're feeling really frisky, I was studying the map of that area and I saw that if you turn right immediately after you head south from Scenic onto Indian Creek Road and take that till it drops into the canyon at this point 43.778067, -102.669395 then bear left, it seems that you can do some more off roading and head south via a tad more engaging route. The map says that road ends but if you zoom in and switch to satellite view, you'll see that it does in fact continue south all the way to this point 43.637680, -102.596513 where you would turn left and come back out on the same road you left in Scenic. I don't know why it's not on the map, but it looks like it would be quite an adventure. Seems like that would be the road that goes through the valley that you will be overlooking from Sheep Mountain at the overlook before it becomes a 4wd road. Not sure how much you'll be hurting for time, but it looks like it would be a good place to explore.

Pay attention to Indian Reservation stuff tho. I don't know how all that works.