jjwillie,
The regular, general season tags are open to the public to where anybody can go to a license vendor and ask for a license and elk tag for (say the sawtooth zone for example) as you do every year. There really is no limit on the # of tags given out in that zone specifically, and the dates are NOT what most would consider "prime" elk hunting dates. Granted, the elk are there as you have witnessed, but the dates are not ideal for say a rut hunt, etc. The controlled hunts are hunts that they set aside a certain # of tags for a certain area and you have to apply for those tags and hope you are drawn. For example, the general season in the sawtooth zone probably starts on October 15th and goes to the end of the month or something close to that. That is pretty close to the GENERAL season dates in most OTC hunt zones. Some of the units they will give a few tags (say for example, 20 tags) that you can apply for that allow the recipients of those tags to hunt from Sept. 15th through Sept. 30th or something like that. Obviously, most people would rather hunt elk the last couple weeks of September when they are in rut but they have to manage those tags and only give a select few away. Those are the controlled hunts you must apply for and draw. There may be hundreds of applicants for those 20 tags, but if you draw one, you're hunting elk at a prime time to be hunting them. It is setup though so you can apply for the controlled hunts and if not successful, still obtain an OTC tag for your unit of choice.
Hope that helps. Not sure if I made myself clear but I'm sure you can get the picture from that.
Jaxon