Evans R. Beck Memorial Nature Preserve, commonly known as Beck Fen, is one of the few high-quality fens that remain of a once extensive wetland system. It was part of a network of fens in the upper watershed of Tinkers Creek within the Western Allegheny Plateau Ecoregion. Today, the fens that remain are Beck Fen, the Conservancy's Herrick Fen and the Ohio Department of Natural Resources' Gott Fen.
Beck Fen was formed approximately 18,000 years ago when the retreat of glaciers left behind large deposits of water-saturated gravel. The cold, oxygen-deficient, alkaline water that flows to the surface provides habitat for fen species.
At least eight different types of sedges dominate the vegetation in Beck Fen. The fen environment contributes to the accumulation of sedge peat and the establishment of additional fen species such as shrubby cinquefoil. The growth of sphagnum mosses in Beck Fen provides an acidic environment for the shrub leather-leaf and the insectivorous round-leaved sundew.
Many rare wildflowers and sedges bloom during the spring and summer at Beck Fen. These include: Blunt mountain-mint, Marsh arrow-grass, Wand-lily, Northern bayberry and Showy lady's-slipper.
Other interesting species include: Swamp milkweed, Great angelica, Shrub leather-leaf, Round-leaved sundew, Bog bedstraw, Water avens, Northern rose azalea, Hoary willow and Autumn willow.