Probably, but in general, the more information you can leave, the better. I think the rescuers would want to know not just that someone survived and was heading downhill towards the road; they might also have wanted to know how many survived (e.g. suppose they followed the arrow and found a body; do they stop searching or not?), whether they were injured, whether they had a compass or orienteering experience, etc. That much information is hard to convey with a pile of rocks, no matter how artistic or creative you are <img src="/images/graemlins/cool.gif" alt="" />