Old-growth forests Forests within Zoar Valley include some of the finest old-growth stands in the eastern United States. Throughout Zoar Valley, a total of of old-growth forest has been recorded; of this, nearly are found within the Zoar Valley Multiple Use Area, with an additional located in the adjacent Deer Lick Nature Sanctuary. which includes an area of large-tree old-growth known colloquially as "The Gallery of the Giants". Hemlock/northern hardwood stands are present and joined by additional
mesophytic plant communities such as beech-maple and maple-basswood forests. Species diversity along the canyon bottom is among the highest in the
Northeastern United States, with more than 20 species occurring in upper-terrace old growth and approximately 10 more largely restricted to younger floodplains and/or lower terraces. Numerous species exceed DBH, and a dozen or more represent the tallest of their kind in New York State or in the entire Northeast. The river is safe to cross at low flows but rapidly becomes treacherous as water rises. Ecological integrity and environmental health of the Cattaraugus are generally good. and the stream regularly experiences elevated
turbidity due to suspended sediments. Some of this sediment load is derived from silt/clay
tills common along the river, but some likely stems from agricultural activities. As is the case with many streams draining agricultural lands,
fecal coliform levels can be elevated at high flows. During summer storm events, especially after a prolonged dry period, bacterial levels can exceed 10,000
colony forming units (cfu); bacterial levels are low most other times. Numerous small waterfalls cascade into the Zoar Valley canyon. Most are cascades, but there are a few straight drops of greater than . Above the falls are dozens of small headwater streams that drain the surrounding uplands. These streams and the Cattaraugus Creek were extensively disturbed by an intense
flash flood in August 2009. ==Recreation==