There are many ways to find a source for the image you want to share. The best way is to use reverse image search. On a computer you just need to drop your image in the Google search bar to find its source. On mobile, you can use one of the reverse image sites, like TinEye. Sometimes it's hard to find the original creator because of all the stolen/uncredited material. You see, posting art without credit encourages other people to do the same. Just because it looks like the image doesn't belong to anyone, most would think it's "public domain". (You would be surprised to learn how small percent of the internet is actually in public domain...) With distinctive images, like our maps, you can try a simple text search as well. If you google "colourful river maps", most results will show you Grasshopper Geography maps. When none of these searches help, and you really want to post that image, simply ask your followers if they know whose work it is. The internet is a huge playground with billions of connections, there's always someone who knows something. After they helped you find the original creator, you can edit or repost the image with proper attribution to avoid future problems.