This time of year it's tough. Home Depot and the likes might still carry some, depending where you are. Do you have a nursery/garden center near you? Otherwise online is your only choice, or wait until Spring.
I guess your other option it to order some online. The shipping fees will kill you though. Might want to look on ebay and see if anyone is offering free shipping...or amazon.
Check out foxfarm.com and locate a business that sells their products. Find the closest place that sells "foxfarm ocean forest" blend or mix. You can thank me later.