I finally got around to checking this trail out. I had passed by its crossing of Old County Road many times, and I guess it just looked like a steep hiking trail right there so I never tried it. Also I think I had crossed it up at the top of the hill while going fast on the Watson Lake gravel road, but had no idea what it was up there.
Anyway, today a friend and I rode down this from the top. Apparently it used to be a road, hell of a jeep road that must have been, steep. Most of the road has been eliminated or covered and the trail routed on and off the old road bed to keep it from rutting. It's not too bad, almost completely rideable but really rocky. Seems like a trail you'd enjoy more with 6" travel, especially in your fork. At 5" it's rideable but you kind of have to be on the brakes a lot. It does pass through pretty areas, though. You come out very close to the culvert-and-stone crossing of Old County Road over Watson Creek. There is another trail section below the road which I'll have to try sometime (so far I never wanted to come out that low on the hill).