I just purchased a home next to three separate trails. We just cleaned the overgrowth. We'd like to place wood chips on the trails. Is there a specific type recommended? Are there more sustainable options? Are there any recommended companies to go through? Would there be any reason not to place wood chips down?
I can't think of any reason not to put wood chips on the trails and have never heard of any downsides, except that wood in the soil competes with plants for nutrients - but that's usually cited as a reason not to use it in combination with potting soil vs. a trail where you don't want plants to grow.
I would say the most common species would be those that are sawn for lumber in the area. And that would be either Douglas-fir or a combination of western hemlock and a true fir like grand fir. Sawmills produce the chips as a byproduct of producing lumber from round logs (i.e., byproducts are unavoidable!).
However, I doubt you'd be able to purchase directly from a sawmill since they sell in truckload quantities to businesses like pulp mills. So you could simply look for businesses selling mulch, chips, gravel, etc. in your area or contact a tree service company since they will often have lots of chipped material from downed trees, trimmings, etc.