James Macfarlane described the area in 1879, "On approaching the lake from the turnpike on the south side, the tourist is startled at finding himself, without any notice, on the brink of a yawning gulf, precisely like that of the Niagara River below the Falls, and nearly as deep.

"[3] Clark Reservation is also noted for its many ferns; it harbors the largest population in the U.S. of American hart's tongue, which is so rare that it was declared endangered in the U.S. in 1989.

Hiking trails skirt a half-ring of cliffs surrounding the lake, as well as traversing the rugged limestone over which the old river flowed.

In addition to staffing the Center, the Friends group also organizes events and retains a naturalist each summer to guide hikes and create nature programming for the public in the park.

[7] In 1879, James Macfarlane purchased the area around the fossil waterfall and the lake, and opened a small resort hotel in the park.

[citation needed] The central part of the current park, amounting to 75 acres (30 ha) and including Glacier Lake and the fossil waterfall, was bought by Mary Clark Thompson in 1915.

[4][15] This fern is quite rare in North America; its presence on the continent was first discovered in 1807 by botanist Frederick Pursh at nearby Split Rock in Onondaga County.

[20] One author has claimed that the conversion of Clark Reservation into a state park in 1926 occurred because of interest in preserving the American hart's tongue fern.

[20] The fossil waterfall and many of the topographical features of Clark Reservation were created about 10,000 years ago, near the end of the most recent ice age (the Wisconsin glaciation).

[23] Roseberry writes, "The abandoned gorges indicate a complex series of glacial rivers parallel to the receding ice front, producing waterfalls when they dropped over north-south ridges.

[26][27] Roseberry writes that this "limestone is deeply waterworn and fissured, mutely telling the force of the deluge which hurled itself over the brink.

Dry Lake is about 12 metres (39 ft) deep and occupies 2 hectares (4.9 acres),[21] and offers an unusual habitat for plants.

As Franco, et al. report, "It is believed to be a karst feature created by dissolving limestone that formed a sinkhole basin.