Thousand Islands National Park area to defend the British from American invasion. Inside the park, Cedar Island, a small island visible from downtown Kingston, Ontario, is the site of a Martello tower named Cathcart Tower. The park was established in 1904, the first Canadian national park east of the Rocky Mountains. It was called "St. Lawrence Islands National Park" until 2013, when it was renamed to "Thousand Islands National Park" to reflect the natural area in the name. In 1997, the park was named one of the national parks with the highest levels of ecological impairment. Animals that inhabit this national park are coyotes,
North American river otter component of their diets. They are less likely to be prey for the North American river otters since they are fast-swimming and can find good escape cover. However, river otters will prey on trout, pike, walleye ("Sander vitreus vitreus"), salmon ("Oncorhynchus" spp.), and other game fish during spawning. Adult North American river otters are capable of consuming of fish per day. A study conducted on captive otters revealed they preferred larger fish, ranging from , more than smaller fish, ranging from , and they had difficulty catching fish species less than or larger than . Otters are known to take