I did a little field trip to Hidden Acres Farm in Greenbluff. They are one of two sources for local jam that we've identified, available at Roseauers. I spoke with Nick, the third generation of farmers in the family. I inquired about them selling at the Millwood Farmers' Market, but he explained that they can't keep up with current demand, even with three people working full time. Apparently they sell a lot of huckleberry products to Japan. Go figure. He did say that other than the huckleberries, they make the jams from the fruit they grow on their 67 acres. Walter's also makes jams available at Yoke's.
I was impressed that Hidden Acres only sells fruit from their farming operations because I've seen the big trucks from Yakima heading up the hill to Greenbluff to supply the tourtist season up there. Yakima fruit is great, but if you're going to go to Greenbluff, it makes sense to me to get fruit actually grown in Greenbluff. Hidden Acres is a good spot for doing that.