How to get close to bird at first light?

[WildTigerTrout]

Go in when it's dark, leave the flashlight in your vest and be as quiet as you can. You don't have to be completely silent though. Turkeys hear all kinds of animals moving around in the dark when they are roosted.

[mikejd]

I have found that moving into place while it is still pitch black dark does not spook a bird. If there is no moon, that much better. No flashlight, just sneak in.

This.
I do it almost every morning. If its still very dark they may wake but will likely not fly. And also if they do fly they will be more huntable since they will try to get back together.

[okiegobblers]

I get as close as I can. The less ground they have to cover, the more apt they are to get curious. I hunt all public land as well, so waiting and calling just leaves more time for other hunters to close the gap.

Very valid point for heavy pressured public land.

[Kylongspur88]

If not posted already, locate him the evening before, go in the next morning in the dark with no light, get tight keep quiet and wait for his feet to hit the ground. Just be careful not to get too close and keep god cover.

If he sees you while still on the roost he'll booger out and fly off while still in the tree. In east Ky that means gliding into the next county. 

[FullChoke]

Another point about sneaking in on him. When you get within 200 yards of his roost and start sneaking under total darkness, remember that this slow approach will take a lot more time to reach your spot than by walking in daylight. Make sure that you allow yourself plenty of extra time when you go in.

[Flintdiver]

Raking a trail in to your best guess as to where they will be is a great tactic. Here in GA we have lots of big quartz, white colored rocks laying around. I grab up a few of those and space them out on the trail, in the trail. One every 10 yards or so. You won't need a light and can very quietly get to position without any noise or a light. The rocks will be your guide. I have killed many using the tactic on a piece of property just like yours.