Backpacking pack recommendations for petite female

I'm looking for a new backpacking pack. I've used an old external frame pack from the 70s and I'm ready to upgrade for weight and distance. My goal to one day do Rainier and if I like it, then Denali one day. I'm also getting into longer backpacking trips. I was ready to just jump on on the BD Mission 75, but I cannot seem to find any info on if it fits well for women. I'd be on the small size according to the size chart. The problem is, I'm a 5'1" petite female. I've looked at the Osprey Xena 85, but can't find if anyone uses it for bigger, longer trips like Rainier or Denali. What do women take on these bigger peaks and longer treks? Any recommendations before I simply buy and try?

If you pack "ultra light", than you can use a frameless pack and only need 35 liters like this:

I wanted to like the 220 mile John Muir Trail - faster and lighter, so I started looking into "ultra light" backpacking.  I was able to share some gear with my hiking partner, but our packs were not heavier than 20 lbs with 5 days of supplies and a bear canister.  We resupplied along the way on the trail and took ~12 days.  

Tips on Ultralight

Go to your local gear shop and figure out your torso length. Many people can be short and have longer torsos, but also short folks can have a lot of leg and have a short torso.
My inseam is around 30” but my torso is around 15-16”, so I have issues finding packs that fit. Once you know what you’re looking for, you might start to more easily narrow down some options. 

I suggest starting here:

https://www.outdoorgearlab.com/topics/climbing/best-mountaineering-backpack/buying-advice

Also, you probably will want to have more than one pack, as you probably will not want to use 75+ L packs for many mountaineering objectives.  You do not need such large pack for Rainier.  

B Swizzle wrote:

Go to your local gear shop and figure out your torso length. Many people can be short and have longer torsos, but also short folks can have a lot of leg and have a short torso.
My inseam is around 30” but my torso is around 15-16”, so I have issues finding packs that fit. Once you know what you’re looking for, you might start to more easily narrow down some options. 

This. There are a lot of good packs out there, but none of them are worth a damn unless they fit you, and there's no one pack that fits everyone. Black Diamond, Osprey, Gregory and Mystery Ranch all make excellent packs, but you have to try them on and walk around with some weight in them in order to find the best match for your body. Find a shop (or shops) that will measure your torso length and let you walk around the store for a while with weight in the pack (sandbags, etc.). 

What are you doing that requires a 75-85 liter pack? As a small/petite person, you'll benefit more than average sized people from keeping your pack weight and bulk to a minimum, especially on steep or rugged terrain. 

I have a short torso and find that the REI Women's Flash packs fit me the best.  I have 2.  One I use for climbing and one for backpacking.   I have lighter packs but none fit me and carry as well. They come in 45 and 55L.  XS, S and M. 

You might try calling Cold Cold World and/or Mountain Tools, they both make big packs and may be able to help you out.  

Have a look at gregory and ortowox's backpacks. They have a lot more focus on making women's versions of their models than most others.

I can suggest checking the utos site. It includes reviews of different stuff for fishing, camping, and hunting. I found out about the solar backpacks there and bought the Voltaic Systems Array Rapid backpack for my wife. I should say, we both were pleasantly surprised. It provides 10Watts of power, charges all USB devices, and provides 25L of storage. The panels are waterproof. The only disadvantage we found is that there is no instruction about the use of this backpack.