A park is a living thing. Not because its filled with living things, but because its constantly a work in progress. Antietam Lake Park is such a place.
The lake itself was created a century ago by damming Antietam Creek. The city of Reading took the further steps to purchase lands surrounding the lake and the source creeks to protect the water supply, which was advanced thinking in that era. (Chicago during this same time was drawing its water from the same part of Lake Michigan they used for sanitation.)
Having secured its drinking water, Reading made the place that held it pretty. The 51 foot dam is a unique design that incorporates a natural looking waterfall as its spillway.
This is one of the two dams. The other is on Antietam Creek, the “seven step dam.” This is a settling dam, designed to reduce the flow of mud into the lake. 
Reading’s efforts only enhanced the natural beauty of the area. Antietam Creek is a typical woodland stream in PA, sitting at the bottom of a pine and hardwood gorge. The lake is surrounded by forest and high hills. It wasn’t only the water that was pure.
After decades of use, Reading wound up getting its water elsewhere. A decade ago they transferred the six hundred some acres of land and water to Berks County for use as a park. This doubled the acreage in the Park System and gave the county an enormous opportunity and perhaps a bigger problem. At this stage in its life Antietam Lake is in need of both repair and direction. While the main dam is structurally sound, there’s no good viewing area for the waterfall due to the fact Antietam and Angora Roads converge at that point. And the picturesque Valve House, the Victorian gingerbread structure jutting into the lake that controlled flow at the dam, is falling down.
Berks County has developed a master plan for the park, but not much progress is visible. Eventually the park will have a dedicated observation area for the waterfall and dam, a pedestrian path from a developed, paved parking area, and a visitor center. At the moment there are a couple of dirt and pothole parking lots, and a couple of dirt and cinder trails rising steeply above the lake and Antietam and Bingaman Creeks. The only major improvement is the opening of the Gravity Trail, six miles of walking and mountain biking path from Mount Penn to Angora Road, and that was the doing of the private Berks County Conservancy, not the park system.
The absence of a polished infrastructure didn’t deter visitors on the Sunday afternoon I hiked. There were fishermen lining the lake, and couples walking hand in hand. A family was finishing dinner next to the seven step dam. Even though people had to walk on the shoulders of the roads to get to the trails, they did it. Fishermen carefully stepped over the road fence to get to good positions to fish near the waterfall – and so did I to get some photos. (Its unclear just where exploration stops and trespassing begins. I saw one faded, small, sign after taking the waterfall photos, which was odd as there was also a sign at the base of the waterfall giving boating regulations.) While Antietam Lake is awaiting the next stage of its life, its very much alive. And so was I as I hiked two miles at the lake.