It's nice to see an independent and useful store. Unfortunately, many independent stores aren't able to carry such a wide selection as your average 'Whole Crap' or 'Trader Craps'. Mariposa Market manages to provide just enough of everything needed for the veg/an, while still keeping that community and local dynamic.
Plenty of veg/an alternatives for meats, butters, sauces and dips, breads, and even a vegan cheese. Nice basic bulk section for dry foods. Fair amount of gluten free items in the packaged and frozen foods section. Produce is well stocked with organic local varieties,plus the usual bananas and out of area fruits.
This is my main shopping spot, and when I come in from the coast I always bulk up on the stuff not available in the smaller health foodstores in my area. Also has a nice selection of basic kitchen and household goods. On my last trip I even found an awesome carry along stainless steel coffee mug which connects to my belt, bag, or anything with a caribener. Filled it up with some organic fresh brewed with sucanat and soymilk before I left!
Definately the best thing Mendo County currently has to offer.