Here is a good example of why they should not be allowed into national parks. https://www.usatoday.com/story/news/nation/2019/05/02/guadalupe-fur-seal-killed-off-leash-dog-california-national-park/3651485002/?fbclid=IwAR171jdKJJNFgzhpEbKDEMfsK9lk1WQKW3Fo9ECcVvNbmnMsIggo0k7NTRA