“Run along the tops of the unique glacial deposits that have become Chimney Bluffs.
— Andy P
While they're allowed on leash elsewhere, signs make it very clear dogs are not allowed on the beach.
The trail edge is at times right at the edge of the bluffs and may not be stable. It can get crowded on the trail, with no good options for passing groups, after 10am on weekends.
Starting from the public parking lot on East Bay Road (restrooms available) the trail ascends a set of stairs. From the stairs, there is a very steep dirt path that is dotted with trees to help less experienced runners. It is this section only (and it's very short—just steep) that would be considered "Intermediate" in difficulty, but once you reach the top, you are at the top of the bluffs. There are typically 2 parallel paths for most of the trail—one right along the cliff's edge (with signs warning that the edge may be unstable) and one 20 feet farther back in the woods. These paths will merge and diverge very frequently.
From the initial ascent along the bluffs themselves, the path is very flat. As you come to the end of the bluffs, the path will gradually descend to 8-10 feet above the lake and continue all the way to the park.
Since there are other trails in the park, you can make your own run by combining them. If you are only running the Bluff Trail, it is recommended to drop down to the beach in any one of a number of openings and paths along the shore and make the return run along the rocky shore. It's a flat run back, but the shifting gravel, stones, and downed trees on the beach require some dexterity to maneuver. But, looking up at the bluff you were on top of a short while ago makes it worth it!
While most runners will focus on the bluffs (because they are so unique) there is decent birdwatching over the lake during migrations.
Beware of the thick poison ivy that is about ankle-to-knee high and on both sides of the trail.