Thru Hike pants

I wore their EchoMesh pants when I hiked the PCT in 2009 from Mexico to the Or/Wash border when the crotch split out. I liked them as I found their venting good while still covering up your legs from direct sunlight and bugs. I treated mine with Permithrin since that wasn't an available option when I bought mine. Having long pants with that treatment (and a long shirt and hat also treated) made the mosquitos tolerable. I hardly used DEET along the JMT portion of the trip as a result since they'd land and then take off again a few seconds latter without trying to bite through. Bring a head net for breaks though. The only downside to them was that when hiking several days in a downpour (ie, the Pacific NW), the mesh inside the pants would saturate and the pants would take longer to dry there as a result since there was double fabric as a result. This is more an issue in your native Washington where the venting isn't needed as much.

I also liked their weatherpants which I used to hike the PCT through Washington in September to early October. They are a bit heavier due to the reinforced areas, but they held up well to crawling under numerous old growth blowdowns in the Glacier Peak wilderness which was still technically closed when I passed through and several days of snow and rain.

you say that you usually hike in pants, but sometimes in shorts. for a short-wearin person who needs pants for a trail, i don't think the ecomesh would leave them wanting more. they are pretty versatile.
a lot of PCTers like the RR ecomesh. Personally, I haven't found their supplex that durable on their ecomesh shirt, ecomesh pants, or weather pants compared to all the other supplex i've worn…
i took runners shorts and a merino bottom and was happy with that configuration fwiw.

I used the Sahara zip off pants from the border to Big Bear. They were very nice, although the zipper area took a long time to dry. If I got new Sahara zip off pants, I'd get the kind that can be removed without taking off your shoes.

I used RR Winter Adventure pants from Fobes Saddle to Snow Creek. I thought that with all the snow, glissading, self arresting and wearing crampons that they'd be perfect. I found that they were way too hot, restricting my stride, and didn't hold up against an errant crampon. At least they were great for glissades and seemed really good at resisting moisture. Still, I won't consider wearing them again unless the temps are in the low teens.

My next pair of long hike pants will be Ecomesh. I like the protection of long pants, but I don't think it's possible for me to wear long pants that breath too well for a PCT thru hike.

Oh, and I think the Adventure pants will be way too warm.

Extremely cool material, 9.9oz for a medium, convertible.

http://www.golite.com/Product/ProdDetail.aspx?p=103001110

Andrew Skurka used these on his recent Alaska/Yukon trip – said he loved the material but thought the fit needed adjustment – but what didn't fit him may fit you well. I haven't tried it yet, but I have Patagonia and Sugoi pants made of the same or similar material and they repel wind well and breath very well and the stretch allows them to move with you.

In warm weather, until I find a replacement, I use an old indestructible pair of Sportif Black Rock ripstop zip-off pants I got dirt cheap from the bargain bin on Sierra Trading Post. Might be the most indestructible synthetic garment for the weight I've ever worn. Far tougher and better made than all the REI pants I tried, which I found to be very poorly made (weak sewing).

This goes without saying – get very light colored pants. Anything darker than beige gets too hot in sunny warm weather.

I'm not a thru-hiker, but I do love my EcoMesh pants. They're certainly not the lightest pant out there, but I like wearing long pants exclusively, and the mesh panels really help keep things cool in warmer weather. It's the only pant I've used (outside of rain pants or winter pants) for the last two years.

"I wore their EcoMesh pants when I hiked the PCT in 2009 from Mexico to the Or/Wash border when the crotch split out."

Similar experience here, with the crotch seam giving way as I struggled through a peat bog in Scotland. Not the best timing, but I was at least able to spend a quiet evening sewing them up in the bothy.

Prior to the trip I also added an extra belt loop at the back of the trousers. Without it I found that the waistband tended to slip uncomfortably under my belt after a while. Regarding the durability of the material used in the Eco-Mesh Pants, I know that Rail Riders changed from Supplex to an unnamed equivalent at one point – I have several pairs of their trousers and also spotted the change in the catalogues – which might account for the difference when compared to other brands. Haven't bought any for nearly ten years (they're still going strong now that I've repaired the rather weakly sewn crotch) so I can't say how the current material compares. As good as they are, though, I do find that they bind around the knee rather badly in rain, so I'm tending to wear stretchier stuff these days, such as Ronhill Trackster Treks.

I like my 5.11 brand nylon "tactical" pants for their durability and $50. price. I prefer them to the equavalent RailRiders pants for features, like the vertical pocket inside the double knees to insert 5.11's neoprene knee pads when scrambling or winter backcountry skiing.

I've givem them double DWR bu washing them in Nikwax and later spraying them well with Revivex DWR. Works very well even for light rain.

Aren't the 5.11 pants partly cotton?

They make both, cotton blend and nylon.

The 5.11 pants definitely hit the "durability" category, almost to a fault. Very sturdy pant and no stretch, so I found them really rough on my knees on a somewhat steep hike last year.