There is an organization in many areas called chipdrop.com . they connect up gardeners with arborist companies for free chips (helps both ways). Of course, you can’t request a set volume, so you may be storing some, which is OK. In my case I contacted our tree guy, because he’s done work for...
@KahKaDoodleDo22 , I live in Western Washington.
I use sand in the covered part of the run. (I don’t think it would work in an open, soggy area, at least here).
In the larger open run I use wood chips (mainly Douglas Fir) from a tree company. They work very well, with whatever organic matter...