It would be a good idea if anyone who goes deep into the wilderness learned how to gather wild foods. You can get lost, a bear can eat your food, and you can lose your pack. Realistically, though, most people won't take the time to learn wilderness survival skills. That is why edible wild berries are such a blessing for all back country travelers.
Edible wild berries look and taste like their domestic counterparts, meaning you can find safe food in the wilderness without training or identification guides. If you know what strawberries, blueberries, blackberries and raspberries look like and taste like, then you can identify the wild varieties. They'll be smaller, but just as full of flavor and nutrition.
When you have time, pick up a good identification guide and go for a walk with it. If you learn a few new berries a year, you'll feel more at home in the wild. On a day hike in Glacier National Park, we ate wild blueberries, service berries, rose hips, blackberries, strawberries, high-bush cranberries, raspberries, thimbleberries and currants. It's a good feeling to be in the mountains and know that there is food all around you.
Can you really fill up on edible wild berries? Absolutely! Wild blueberries on rocky little islands in Lake Superior kept a friend and I from going hungry during a kayaking trip (we underestimated our food needs when packing). I did the math, based on the calorie count per ounce, and found that we could eat 500 calories of berries in an hour. With wild raspberries in the Rocky Mountains, I found I could gather and eat 500 calories in less than 30 minutes.
Start by tasting the next edible wild berries you see. If it taste like a raspberry, it is a raspberry. If it taste wrong, just spit it out. There are not many wild berries that look like a raspberries, strawberries or
blueberries, and virtually no berries in North America that can poison you from just a taste (except poison ivy berries - so avoid white berries if you are unsure).