Although no wildlife survey of Euclid Creek had been conducted as of 2006, anecdotal evidence indicates that wildlife supported by the stream is typical of that found in an urban area with extensive greenspace: beaver, great blue heron, mink, red fox, white-tailed deer, wild turkey, and a small (and perhaps transient) population of coyotes in the Acacia Reservation.
Although no known endangered or threatened amphibian, fish, invertebrate, or mammal is known to exist in the Euclid Creek watershed, the lack of extensive studies means that their presence cannot be ruled out.

Only a small number of areas, limited in size, have been studied to identify plant species within the Euclid Creek watershed.
One endangered plant and two uncommon plants are known to exist in the area.
Solidago puberula ("downy goldenrod") is a perennial herb listed as endangered in Ohio by ODNR.
The only known stable population of this plant species in Ohio is found in Highland Heights Community Park near the headwaters of a tributary of the east branch of Euclid Creek.
Hypericum gentianoides (a species of St. John's wort commonly known as "orangegrass" or "pineweed") and Rhynchospora capitellata (a species of sedge commonly known as "brownish beaksedge" or "brownish beaked-rush") are also found in wet areas of Highland Heights Community Park.
This is the only known location in Cuyahoga County for either species.

As a highly disturbed stream, Euclid Creek is heavily impacted by a large number of invasive plant species.
Phragmites australis (a perennial grass) is extremely common north of Euclid Creek Reservation and in nearly all places where the stream banks have been disturbed.
Alliaria petiolata (garlic mustard) and Reynoutria japonica (Japanese knotweed) are found extensively north of Euclid Creek Reservation.
Other common invasive species throughout the watershed include autumn olive, buckthorn, several species of bush honeysuckle, Canada thistle, Japanese honeysuckle, multiflora rose, narrow-leaf cattail, purple loosestrife, reed canary grass, Russian olive, and tree of heaven.
Although no wildlife survey of Euclid Creek had been conducted as of 2006, anecdotal evidence indicates that wildlife supported by the stream is typical of that found in an urban area with extensive greenspace: beaver, great blue heron, mink, red fox, white-tailed deer, wild turkey, and a small (and perhaps transient) population of coyotes in the Acacia Reservation. Although no known endangered or threatened amphibian, fish, invertebrate, or mammal is known to exist in the Euclid Creek watershed, the lack of extensive studies means that their presence cannot be ruled out.
Only a small number of areas, limited in size, have been studied to identify plant species within the Euclid Creek watershed. One endangered plant and two uncommon plants are known to exist in the area. Solidago puberula ("downy goldenrod") is a perennial herb listed as endangered in Ohio by ODNR. The only known stable population of this plant species in Ohio is found in Highland Heights Community Park near the headwaters of a tributary of the east branch of Euclid Creek. Hypericum gentianoides (a species of St. John's wort commonly known as "orangegrass" or "pineweed") and Rhynchospora capitellata (a species of sedge commonly known as "brownish beaksedge" or "brownish beaked-rush") are also found in wet areas of Highland Heights Community Park. This is the only known location in Cuyahoga County for either species.
As a highly disturbed stream, Euclid Creek is heavily impacted by a large number of invasive plant species. Phragmites australis (a perennial grass) is extremely common north of Euclid Creek Reservation and in nearly all places where the stream banks have been disturbed. Alliaria petiolata (garlic mustard) and Reynoutria japonica (Japanese knotweed) are found extensively north of Euclid Creek Reservation. Other common invasive species throughout the watershed include autumn olive, buckthorn, several species of bush honeysuckle, Canada thistle, Japanese honeysuckle, multiflora rose, narrow-leaf cattail, purple loosestrife, reed canary grass, Russian olive, and tree of heaven.
Euclid Creek