Len, you can also pick up most roadkill in BC if you have a trapper's license. 
 
 i usually wild harvest a significant portion of my food and medicinal (tea) plants. lots of mushrooms, berries, nuts (hazel, walnuts), apples/pears/medlars and edible greens.. all from wild/feral/otherwise untended areas.
 
 i also am in to hunting, fishing, trapping, and using parts of animals that others usually toss (heads, hooves, hides, bones, etc.). i also enjoy clamming and picking oysters and mussels. 
 
 sometimes we'll get free animals from the buy and sell/craigslist, too. got a free boar once! 
 
 anyways, when i have a stable living situation and can focus on food i would guess alteast 75% of my food comes from the above methods. i also grow some veggies by just encouraging them to go feral (ideal) and i usually tend atleast a potato patch and some squash plants.