Hi Rick, and welcome to the forum!

High CYA and salt systems really don't have anything to do with each other, except that IF you have a salt system, you also have to have a high CYA to make the salt cell work at its highest efficiency.

If the chlorine granules that you are using are dichlor, then yes, that's what's causing your high CYA. At this point you have a few options:
1) Switch to a SWCG system that will require you to have around 80 ppm CYA, and it will use the salt to generate your chlorine, eliminating the need for you to have to manually chlorinate the pool, or
2) Drain some water and refill with fresh in order to lower that CYA level, then stop using stabilized chlorine and switch to Cal-hypo or bleach, or
3) Simply raise your chlorine levels to compensate for the high CYA, which is probably your best (and definitely your cheapest) alternative, especially in Texas. Check out the link to the "best guess chlorine chart" in my sig for more information there.

Regardless of the route you choose, you DO need to stop using the stabilized chlorine, if you don't want your CYA to go any higher. Once it's in the water, it's there--the only ways to lower it are through splashout, water drain, or letting it go swamplike (which has a whole 'nother set of consequences, so I wouldn't even consider that one.).