I dont see why you couldnt start one? Perhaps put up flyers around your area to see how many people you can get interested in it.
Im sure you would be very surprised at how many people you might find. You might even find someone who knows a lot about robotics! For your first meetings/get-togethers, you can talk about what you all want to accomplish. Set up small goals for yourselves! Say "We should build a robot that can [insert function] and [insert function]" and then go about researching how to do it. The SoR community could be your research and guidance tool for the most part. With of course each member contributing in any way they can, You could all learn together and who knows, maybe a little while into it, you can maybe even be competing in the DARPA competitions winning high places!!
Seriously, its worth a try. You could even get sponsors. Perhaps if you went to a machining shop they would let you use their equipment for a while when they weren't...