I arrived in Denver by train and immediately got hit with altitude issues. I don’t get altitude sickness exactly, but I do get winded when I have no time to adjust. Along my way north, I stopped at Rocky Mountain National Park. Unfortunately, because it was even higher, I could not do any hiking as I was just getting hit too hard by the altitude. Instead, I spent an enjoyable afternoon driving around and looking from the outlooks. One part of the park that I thought was special was how evident the tree line was. As the road approaches the highest part of the park, there are signs noting that you are entering an alpine environment, which is a sensitive ecosystem. The views are lovely.