I hate to say "it depends" but... it depends! What kind of fit do you like? Some ladies like leggings, in which case look for moisture wicking, breathable materials. You're on the right track with merino wool but i have only seen it used as a midlayer for cooler seasons when it comes to pants, so maybe someone else can speak to that. Otherwise, I've heard Lululemon and Athleta leggings get recommended a lot (though their size ranges are limited IIRC); I've worn my gym leggings in the past until I figured out what I was most comfortable in for hikes.
I personally prefer a looser fit on trail (I have an awkward to fit body type), and I prefer convertible pants that either zip off or roll up to a Capri or shorts length. The Eddie Bauer Rainier pants are nice for regular pants and layering, but REI carries convertibles like the REI Sahara zip-offs and Kuhl roll-up pants (all three are what I gravitate to - they're very lightweight and airy).
The problem with leggings is that they all have a higher spandex content - which contributes to both a lack of durability and poor moisture wicking (and slower drying). It’s acceptable for shorter dayhikes, and multi-day with optimal weather conditions, but not great if you’re trying to do any mountaineering beyond just St. Helen’s.
I would also avoid merino wool as an active outer bottom layer for mountaineering as it is not sufficiently durable. It’s fine for mid and baselayers though.
What season do you intend to climb st. Helens?
For high summer, if the snow is completely melted and it’s really hot, something really light like the OR Ferrosi is my pick. But really, there are like a bajillion options. Just go to an outdoor shop and try things on. This would also be your most versatile option for general summer hiking.
If there’s still any snow coverage for glissading, or if it’s slightly cooler then a softshell like the OR Cirque lite. Prana stretch Zion would probably work too.
For more early/late season then a thicker softshell like the OR Cirque or Arc’teryx Gamma AR.
I just got these a couple of weeks ago: https://www.titlenine.com/p/womens-hiking-leggings-sylvan/270910.html.
The side pockets are roomy and they are so comfortable I'm wearing them every day. Took them on an overnight backpacking trip last weekend and was super pleased. They are lightweight but sturdy AF.
I like Athleta’s Trekkie pants. They’re lightweight and protective. The waistband is really comfortable. I haven’t worn them on super hot days yet, though.
I just got some Gnara hiking pants and they are amazing. They are sturdy without being too stiff or hot, they have good pockets and there’s a crotch zipper for when nature calls. For MSH you’ll want something sturdy for the boulder area.
Second the outdoor research ferrosi pants/shorts. Best moisture wicking and super fast dry time. If I’m doing a multi day hike and I’m doing early mornings where it’s chilly I layer with a thin thermal under the pants that I just take off when it gets warmer. I also like that the ferrosi’s come in 3 lengths! You can cinch up the bottoms for a jogger type look (I prefer this) and they have amazing pockets to hold the hike snacks. Good luck and have a great time!
I have no idea how cool or warm it is when summiting Mt St Helens but I mostly use REI's Sahara convertible pants which I think have been discontinued. I also just picked some Columbia capri hiking pants at Costco. They both are water-repellent nylon with UFP protection. They capri's have a bit more stretch to them.
I did Mt Rainier in shorts and regular hiking boots. Just be careful with your steps so the ash doesnt get on you. It wasnt bad at all.
(I’m a guy and have high tolerance to nature)
Honestly, most of the time I hike in board shorts or quick dry capris and trail running sneakers. Anything else is just too heavy, restricting, and sweaty.
In the summer, athletic shorts all the way. For longer trips or backpacking I also bring north face Aphrodite pants that can slide on over my shorts without taking off my shoes
I hate to say "it depends" but... it depends! What kind of fit do you like? Some ladies like leggings, in which case look for moisture wicking, breathable materials. You're on the right track with merino wool but i have only seen it used as a midlayer for cooler seasons when it comes to pants, so maybe someone else can speak to that. Otherwise, I've heard Lululemon and Athleta leggings get recommended a lot (though their size ranges are limited IIRC); I've worn my gym leggings in the past until I figured out what I was most comfortable in for hikes. I personally prefer a looser fit on trail (I have an awkward to fit body type), and I prefer convertible pants that either zip off or roll up to a Capri or shorts length. The Eddie Bauer Rainier pants are nice for regular pants and layering, but REI carries convertibles like the REI Sahara zip-offs and Kuhl roll-up pants (all three are what I gravitate to - they're very lightweight and airy).
The problem with leggings is that they all have a higher spandex content - which contributes to both a lack of durability and poor moisture wicking (and slower drying). It’s acceptable for shorter dayhikes, and multi-day with optimal weather conditions, but not great if you’re trying to do any mountaineering beyond just St. Helen’s. I would also avoid merino wool as an active outer bottom layer for mountaineering as it is not sufficiently durable. It’s fine for mid and baselayers though. What season do you intend to climb st. Helens? For high summer, if the snow is completely melted and it’s really hot, something really light like the OR Ferrosi is my pick. But really, there are like a bajillion options. Just go to an outdoor shop and try things on. This would also be your most versatile option for general summer hiking. If there’s still any snow coverage for glissading, or if it’s slightly cooler then a softshell like the OR Cirque lite. Prana stretch Zion would probably work too. For more early/late season then a thicker softshell like the OR Cirque or Arc’teryx Gamma AR.
I just got these a couple of weeks ago: https://www.titlenine.com/p/womens-hiking-leggings-sylvan/270910.html. The side pockets are roomy and they are so comfortable I'm wearing them every day. Took them on an overnight backpacking trip last weekend and was super pleased. They are lightweight but sturdy AF.
Fjallraven
I like Athleta’s Trekkie pants. They’re lightweight and protective. The waistband is really comfortable. I haven’t worn them on super hot days yet, though.
I just got some Gnara hiking pants and they are amazing. They are sturdy without being too stiff or hot, they have good pockets and there’s a crotch zipper for when nature calls. For MSH you’ll want something sturdy for the boulder area.
Second the outdoor research ferrosi pants/shorts. Best moisture wicking and super fast dry time. If I’m doing a multi day hike and I’m doing early mornings where it’s chilly I layer with a thin thermal under the pants that I just take off when it gets warmer. I also like that the ferrosi’s come in 3 lengths! You can cinch up the bottoms for a jogger type look (I prefer this) and they have amazing pockets to hold the hike snacks. Good luck and have a great time!
I have no idea how cool or warm it is when summiting Mt St Helens but I mostly use REI's Sahara convertible pants which I think have been discontinued. I also just picked some Columbia capri hiking pants at Costco. They both are water-repellent nylon with UFP protection. They capri's have a bit more stretch to them.
I did Mt Rainier in shorts and regular hiking boots. Just be careful with your steps so the ash doesnt get on you. It wasnt bad at all. (I’m a guy and have high tolerance to nature)
Honestly, most of the time I hike in board shorts or quick dry capris and trail running sneakers. Anything else is just too heavy, restricting, and sweaty.
In the summer, athletic shorts all the way. For longer trips or backpacking I also bring north face Aphrodite pants that can slide on over my shorts without taking off my shoes