I'm trying to create a map in the style of maps made in the 19th century, such as this one.

In general I think I know how to proceed. However, what I'm still unsure of is how to show particular terrain features, such as forests, swamps, deserts and so forth - most of the maps I've seen only show mountains and rivers. If you have any good examples of period maps with such elements, or any other good suggestions, please tell me about it!