I did this as an out and back from Hendricks. It was uphill out and downhill back (smart choice).
I started at 10am and it was still cool. The trail is a non-stop climb for the first half so by the time I hit the turnaround at Thomas I was quite sweaty and thirsty. I carried 2L of water but was running low. There was a small bar and grill with a bubbler and they invited me to refill my water there. I turned around at the dam. I carried enough gel to get through the run. The run back down was more exhausting because I was tired, but it still went faster. One thing to note - it looks like you can refill water from the river along the way, but you can't. You're many hundreds of feet above the water running parallel to it. Also, you'll probably want bug spray in the summer. I think I ate as many bugs as I got bitten by everytime I stopped.
I saw 2 people at the start biking and then no one else until Thomas. There were a few people within a half mile of the trailhead in Thomas but that's it. Overall, very quiet. The attached photos of the trail show how narrow and overgrown it is in some places.