bull snakes vs rattle snakes

Question
I have looked on-line, and none of the sites seem to include an actual pictoral comparison of the two types of snakes.  I walk on the trails near where I live and I am unsure if the snakes are, what we call, forrest rattlers or just bull snakes which pretend to be rattlers.  I give them a wide berth, but the trail curves a lot and I don't wish to frighten them by accident and get bitten.  One of the snakes I have seen had a distinctly traingular head and a distinct rattle, the other ones do not.  It is my understanding that some bull snakes can look almost identical to rattle snakes, so how can I tell the difference?

Answer
Go right to my snake page on wichitafallsreptilerescue.webs.com and you will see plenty of comparison. There are no "Forest rattlers" as a common name usage, so assuming you are in the east, rattlers you see are probably Canebrake, Timber, or Eastern Diamondback.