I live in Stillwater and am trying to find somewhere to buy straw bales, which is apparently hard to find this time of year.
I tried AtWoods, the milling company, and looking in shop and swap and craigslist, but no luck.
Try local feed and seed stores that are not part of a big chain. I have the best luck with those. This is sort of the wrong time of year to find straw though unless you're in an area where the wheat harvest has begun. At this time of year, that likely would be SW OK or southern OK. All I've seen at feed stores lately is some very pricey clean coastal bermuda hay for horses and sometimes alfalfa hay.
If you want straw for mulch this early in the year, you may have to settle for some sort of hay, which can be problematic because it often contains weed seeds. I sometimes get around that by putting a double layer of cardboard or thick layers of newspaper underneath the hay. That keeps seeds in the hay from reaching the soil and sprouting.
If you have local horse stables, you might call and ask them if they use straw for bedding and, if they do, if they'll tell you their source as you wish to buy some clean straw for mulch. However, a lot of horse people buy bagged beddng at feed stores nowadays instead of buying bales of straw so they may not be able to help you.
Finally, you might try looking through the listings at the OK Hay Exchange website to see if anyone is offering baled wheat straw yet or keep watching for when it pops up there. I'll find it and link it below.
Here is a link that might be useful: Hay Exchange
Post in craigslist that you are looking for rain or water damaged bales. This time of year good undamaged bales are impossible to find.
I got mine for free as they were the bottom layer of a stack and farmer couldnt sell them. He would have had to pull them out and burn them.
When I am faced with a problem like that I mow the lawn, let the grass dry a day or 2, then come back and windrow it, then come back and pick it up with our small grass catcher. I then place it on top of a thick layer of paper in the beds (thin layer of grass). It is not pretty, but it will hold me till I can find what I really want to place on top. I like a light color mulch but use what ever I can find for free.
I got my wheat straw at Circle E in Edmond.