Hi Jasen, thanks for your comment. While it’s true that many national parks don’t have mountain biking trails and even fewer allow dogs on their trails, most parks are surrounded by national forest lands where both are allowed. There are several reasons why dogs aren’t allowed on national park trails, probably the biggest one being the fact that national parks are preserved wilderness areas. Animals from the “outside” don’t really have a place there. Luckily, though, there’s tons of space all over the US where you can take both your bike and your dog!