Er's blog claims that national parks are the best vacation destinations. which evidence is best for de
personal account from a park visitor who describes positive adventures at grand canyon and yellow
n interview with a travel agent who advertises cruises, eco-tours, and whitewater rafting trips
chart that compares the number of national parks in the eastern united states to that in the westers
study that proves adults who take yearly vacations have lower blood pressure than those who do now