You can drive all the way to the top if you just want a view of the dam. The hike up is decent from the visitor center but most of the view of the river below will be blocked by trees in the summer. The bluffs overlooking the trail are still a nice enough view to make up for it. I didn't even mind the vultures circling me like they knew something I didn't.
We completed the trail on a warm December Saturday and had the entire trail to ourselves. We parked at the Visitor's Center (which was closed for the season) and then walked up the road to the end and the nice overlook. I recommend this route as there is another nice overlook along the road that you would miss if you just hiked the trail out and back.
From the second overlook (and the end of the road), you descend several stairs and the trail leads back to the visitor's center. The trail is easy and was no problem for my family, including my energetic six year old boy. There are a couple short wooden bridges along the trail and plenty of views of the river and the dam.
The trail itself was very clean - I did not see a single piece of trash. The problem of people leaving things behind on trails seems to be a common problem.
We found signs for two more trails in the area - Josh Park Trail and Collins Creek Trail.
If you are with small children, be sure to head over to the fish hatchery and follow the road through the camping area. There is a nice little playground for the kids that is right next to Collins Creek with ample seating and shade for the adults.
This is a nice trail I run nearly weekly, being a local resident of Heber Springs. As mentioned, it's a pretty quick trail to hit, has a few nice streams with a view of the river below in some areas. All around a beautiful trail for a quick hike or technical run. You can start the trail at the visitors center, or at the top of the trail where the overlook of the dam is.
If you're into running trails like myself, you can start at the overlook, and head down the trail and cross the street in front of the visitors center where the road is blocked off. This will bring you into the park area where you can run around a part of the lake and it joins into Josh Park trail. Depending on how you route it out, this can turn it in to a 6-8+ mile out and back. Conversely you can start out at Josh Park, which is what I usually do.
Anyhow, it's a nice little trail, especially if you're in the area.
There has been some more parking spots newly added along the road that parallels the trail. Road is just up hill a bit and if you just want to walk its a good walk to the overlook. At least one pick nick table. You can park along this road and get onto the trail at several spots along the way. During the week almost no traffic. On weekend too much. You can also get to trail from the trail at Dam Site Park which is across the hwy.
Well maintained trail next to the visitors center. Start at the visitors center and follow the trail to the stairs and overlook at the end. Retrace your steps to return the parking lot. I am not sure why the description refers to it as a loop...it is not. It is 1.6 miles out and back (round trip).