Blackhawk is right.You have your work cut out for you.Probably the last thing I would want to do in that situation is sit on water or anywhere else.Not that mule deer or elk can't be taken at water sources but animals who know they are being hunted get very sharp and most animals are very nervous around water,in the best of times.Water is where animals converge so water is a prime place for predators to lay in wait.Prey animals get it.That's how they stay alive,day to day.
In a high pressure situation,water or food isn't enough of a draw to make mule deer commit suicide.They can wait till dark to get a drink.
I was born,raised and lived the first 2/3'rds of my live in the East,so I can say this.Easterners like to sit and it comes natural.Most Western animals when unpressured,don't have real,defined travel patterns.They may travel a trail 2 or 3 days in a row or never.They may come to the same,mile long,irrigated field every night to eat but I've glassed individual bucks,day after day and one day they enter at one end of the field and the next day,they enter at the other end,3/4 mi. away.They leave the field in the morning,traveling up a very steep draw,but in the evening,come out to the field using a completely different draw,1/4 to 1/2 mile away.
That's unpressured.Add pressure to that and they may move 2 or 3 miles each day.
Scouting before season won't tell you what deer will do if they are pressured.The only thing you can do is keep moving and glass,glass,glass.Move till you are into deer then observe with your glasses and try to come up with a plan.Don't be afraid to think outside the box or try to make something happen.
Keep in mind,in the mountains,thermals move down the mountain in the morning until the temperatures start to rise.Most animals move up long before the thermals shift.Sitting,waiting for them is impossible,especially with short ranged weapons.You are sitting right in their windstream.
Your best option in this situation is to stay back,glass and put one to bed.After he is settled in,make a stalk,sidehill or whatever works according to the wind.When you start your stalk,which often takes you in a wide arc to get out of line of sight,mule deer will often get up,move a few yards and bed again.They may do this several times before they get up in the evening.If the mulie is bedded below a rock,don't get tunnel vision.When you get there,he may be 20 yds away.
Anyway,good luck.Take lots of pictures and enjoy your time in the mountains.At daylight,get to a place where you can glass and pick apart the landscape till you have seen every deer.No deer? Move.An hour or two after daylight you are no longer looking for deer.You need to look for antler tips,ears,bedded deer etc.
Move and glass till you are into deer,then move till you are within bow range.Most times,if you are sitting waiting,for a deer you can't see,you will be waiting a long time.I'm not saying that they won't come into a water hole,just don't stake your whole hunt on it.You can figure that out when you get there.A small trail camera could let you know if your waterhole is being hit during daylight.