Hills on a town map

[C_Splash]

I am nearing completion with a town map I am working on, but have hit a snag. I need to make it look like there are hills on parts of the map, but don't know how to do so on a map like this. Here's the map in question:
Graymont Hills Help.jpg
I've highlighted in pink where the hills are meant to go. I would appreciate direction to a good tutorial for this. Thanks!