Olaf, your player is running his character intelligently and has built him to do just what he is doing. Whatever you do, resist the temptation to punish his character for being effective. Just mix things up a bit. Right now, sure he's devastating with his bow. Let him enjoy his shining moment.
By diversifying the challenges you throw at your party there are going to be times when your archer is next to useless and the other players get to enjoy the spotlight. You have a cleric in the party? Well, how about the next adventure finds the PCs investigating a haunted keep full of undead with maybe a few of these...
STONE GIANT SKELETON CR 6
Monster Manual 124 and 225
NE Large undead
Init +6; Senses darkvision 60 ft.; Listen +0, Spot +0
Language understands, but cannot speak Giant
AC 17, touch 12, flat-footed 14 (-1 size, +3 Dex, +2 natural, +3 hide)
hp 91 (14 HD); DR 5/bludgeoning
Immune cold
Fort +4, Ref +4, Will +9
Spd 30 ft.
Melee 2 claws +14 (1d6+8)
Space 10 ft. Reach 10 ft.
Base Atk +7; Grp +19
Abilities Str 27, Dex 17, Con –, Int –, Wis 10, Cha 1
SQ undead traits
Feats Improved Initiative
And how about tossing in some incorporeal undead.
Or how about some puzzles, problem solving... things that maybe the rogue in the party can get some time to shine. You might even try some challenges that the archer gets to be the star in which it doesn't require pincushioning the bad guys. How about trapping the party in some way that requires the archer to strike a far away button that deactivates some kind of big iron cage with inverted spikes that's slowing closing in on them. He's only got so many arrows, right? Think about the tension that builds each time he misses, the walls keep closing in, and he's down another arrow and cursing himself for wasting them on those stupid kobolds they just encountered.
There's a lot of ways to deal with really well crafted characters to challenge them. You don't have to beat them down. Just keep a good amount of variety coming at them... some things they may suck at, like dealing with a dire bear that's grappling them... others he'll be utterly unstoppable at like taking out a whole party of orcs out in the open before they ever get a chance to close for melee.
Anyway, hope some of my suggestions help.