For anyone interested or that has the same questionsl, I've done a bunch more reading on the topic and I think I have found my answer. For starters, I didn't realize that there was a difference between the roots and the rhizomes. Again, probably common knowledge to many. The roots actually grow down and out to provide stability to the plant while the rhizomes grow closer to the surface and outward parallel(ish) to the ground. I ran across a pdf on the freshhops site that is about hop farming. It sounds like what the author recommends is tilling the soil around the crown throughout the season if you'd like to prevent them from spreading, at least for larger scale farming. In the spring it sounds like you can also till up the soil around your crown area to dig up the new rhizomes from the previous year. I think that this will likely become my method. I don't have a ton of space for my hops in my garden so they will be pretty close together, I'll have to keep on top of it every year to ensure that they don't get mixed together and that they don't spread out of control each year.
If anyone is interested, this is the pdf I ran across: http://www.crannogales.com/HopsManual.pdf
The details on annual maintenance are on page 25 or 26, depending on if you're using the pdf page number or the page number in the document.
If anyone else has any advice on how difficult this annual maintenance is or how to best accomplish what I'm after, I'd appreciate it.