Hiking/trekking lens

I've read a lot on these forums about favorite "walk around" lenses, but being an avid hiker/trekker, "walking around" for me may mean hiking up to 15 or 20 miles a day. I have a 30d and would like a lens that wouldn't be too much of a burden on a long hike but that has good image quality and a decent zoom range. Was thinking of the efs 17-55 IS but figured I'd get recommendations from those who might already have a favorite lens they use for their treks in the mountains.

I do a lot of B/Ping and hiking and I always grab my 70-200 f/4
over my 17-40. My 17-40 is currently up 4 sale and I'm getting
the 24-70. I will keep it down to the 24-70 and the 70-200
when I hike, and most likely on my 30D. I have a feeling the
the 24-70 will be on my 30D when I have to make a one lens
choice for hiking...

--
Logic is superior to emotion
BUT
Emotion is much more fun!

Watch out for the exposure police.
They will tell you that its wrong even
though they weren't there to witness it.

Come visit me at:
http://www.pbase.com/keithallenlaw
See my profile for what i shoot with.

Its built very well and attached with my 30D it fits well in my hydration pack for b/hiking.

If it was one lens, mine would be the 17-85 IS. I know it cops a lot of flak but having taken this with my 350D up Mt Kilimanjaro (my one and only serious hike), I found the light weight, zoom range and IS to be necessities for my shooting needs.

I'm finding the 17-40 zoom and the
100 f2.8 macro to be a good hiking
combination with the Canon 5D.
A Gitzo 1327 is a very nice tripod
for hiking; not too heavy.

maljo

400D/Xti +
Tamron 17-50/2.8 (smaller and lighter than Canon 17-55/2.8) +
Canon 55-200 (surprisingly good for the money)