DO NOT eat mushrooms. Do Not eat any plant with milky sap unless you know for sure that it is edible. Some exceptions are wild figs and dandelions. Teas can also be made easily from pine needles which are always available in any elevation. Look for Fir, Pine, and Spruce because these particularly contain high amounts of absorbic acid which is an essential nutrient that will help prevent scurvy and other bone debilitating disease.
Scurvy can happen quickly so always drink as much natural tea as possible.
Always remember, avoid shellfish, although sea urchin like starfish are edible anytime. Most shellfish have certain times of the year they are good, other times they emit toxins that can make them deadly. Starfish and other urchins can be split open and the insides and eggs should be removed and eaten. All fur bearing animals are edible. All birds are edible with no exceptions.