Mountaineering, Climbing, Backpacking, and Camping: Tell Someone Where You are Going
It's a simple thing, but a) we don't always follow it, and b) people just starting out need to know it. Your plan shouldn't stay with you. We should all be telling a trusted person our itinerary and route before every trip into the backcountry. It will dramatically improve the odds of you receiving help should you need it.