You don't have to know where they are, but you do need to know what the wind is doing when you're planning your route. I can promise you this, if elk are in an area & the wind is going from you to them, they will not be there a few seconds later & you'll never know they were even there to start with.
Watch some videos on YouTube & learn the concept of thermals.
Wind isn't as critical when rifle hunting because you can still get a shot if you spot them 400 yards away, but for archery it's the single most important thing