My new personal project right now is making an illustrated map of Yellowstone National Park. I had the pleasure of having visited there last summer during my westward road trip. I know it's cheesy but seeing the forests and mountains there have left a lasting impression on my mind, and I would like to transfer this into a piece of work. Here are some cool reference pictures I've found that are becoming my inspiration.
I plan to combine some traditional map layouts, with some hand lettering, and little spot illustrations of the different attractions and animals. If you've never really checked out Yellowstone, Ken Burns has a great series on pbs called "The National Parks: America's Best Idea," that features yellowstone and many other beautiful sites in the US.