Dos Rios Ranch set to be newest California park December 2, 2022 Home Explore The Naturalist's Journal Dos Rios Ranch set to be newest California park Share FacebookTwitterEmail At the point where the Tuolumne and San Joaquin rivers converge near Grayson, River Partners has been leading the decade-long effort to turn the clock back for the 2,100 acres at Dos Rios Ranch. What was a working dairy and almond orchard has been transformed into and environment resembling the natural habitat it once was, long before the soil was ever tilled.