Recommend Non-convertible cargo pants for backpacking

I haven’t checked the fabric, but the Kuhl Silencr cargo pant (or a different Kuhl model) might work for you.

Edit: Just checked and the Silencr is polyester. I think they’re great. However, they might make some other styles in nylon. I used to have a pair from MontBell that I liked, maybe check there.

I thought I just ordered a pair of the REI Sahara pants without zip-off legs, but it turns out it was over two and a half years ago.

I used the REI sahara convertibles for many years.  About 4 years ago, I went with non convertible as I found I just didn’t zip off to shorts that often.  For that time, I have been using Railriders adventure khakis and have found them to be much more durable (and even lighter) than the REI saharas:  https://www.railriders.com/men-adventure-khaki-pant-p-877.html?cPath=90_102

Eddie Bauer Guide Pro.  If super hot and you must have long pants,  then maybe something else much thinner and baggy. I like much them better than any of the Kuhl versions I have and the Guide pRos have lasted much longer and still look good.

I don’t know what you’re looking for in terms of fabric texture, bit it looks like the trend in hiking pants is toward stretchy fabric and cargo pockets that don’t stick out. I recently picked up a pair like this which feels nice to walk in, but the cargo pocket (only one) is smaller than the huge, fully external pockets I’m wearing right now. I’ve only worn the stretchy pants on one dayhike so far and there is a noticeable difference in freedom of movement. The stretchy cargo pocket had some advantages; lower profile and less bounce. The potential disadvantages I can see are durability and loss of elasticity over time. The stretchy pants felt kind of like sweat-pants; very breathable and nice on the skin. But I wouldn’t want to go off-trail in them.

Railroaders. I have been using them for years very comfortable and last forever

OR Ferossi Cargo Pant – really nice, lightweight pants. Really like these in warmer weather. Nice stretch, generous pockets. Drawcord in cuff.

Prana Stretch Zion – also nice. Heavier material that I don’t find vents well. But really nice stretch, very comfortable. You can roll up the cuffs and snap in place – helps in warmer weather. These are probably my go to all-around pair of pants.

Outdoor Vitals Satu Adventure Pants – The material is Ok, but not my favorite. Has a sheen, texture, and fall that has a feel of a cheap rayon suit. That aside, great features and in particular, side vents. Zippers on the outside of your legs from about knee up to the hip, with a mesh interior. Unzip them and the heat just dumps out. Love this feature.

Railriders with side zip mesh vents.  Incredibly versatile.
https://www.railriders.com/men-eco-mesh-pant-with-insect-shield-p-837.html?cPath=104_110

I prefer to keep the weight of my pants low when I can.  I usually go for loose, blousy running or wind pants.  Elastic waist, no pockets, 2 ounce per square yard or less fabric.  They typically weigh about 5 ounces instead of about 10 ounces for the heavier pants. even though I usually buy an XL size for my medium body.

In the past there were a lot of these in the 2nd hand stores.  Haven’t bought any recently.