Southwest Ridge Approach
This 1-2 hour hike offers nice views and a challenge you wont find in merely driving to the top of Vinegar Hill. Also, depending on road conditions, you may not be able to drive to the summit, in that case this route is direct and not overly difficult.
10 miles up Forest Service Road 2010 just before Black Butte Camp is a cattle guard and sign notifying that you are entering the Vinegar Hill - Indian Rock scenic area. Parking at Black Butte Camp, backtrack the short distance to the cattle guard and climb the ridgeline following the remains of a barbwire fence to peak 7738, a subpeak of Vinegar Hill.
From this peak you will see your next obstacle across a saddle, a short rock cliff with a chute up the middle of it that can offer a break from the monotony of hiking with a little class 3 rock climbing. This rock face can be circumnavigated easily to the left if your not interested in the direct route.
Once you have made the top of this rock face, follow the ridge spine less than a mile to the remains of the lookout. There are several false summits along this route, you will know the true summit as it has a rock foundation on it.
To return head west off of the summit to the road below, follow it a short ways into a clearing which you can cut down and meet back up with the road below saving yourself a huge switchback. Follow this road south back to Black Butte Camp. Roundtrip this route has roughly 1300 feet of elevation gain and runs about 3.2 miles.