My student’s at Whitman, I’d be happy to answer any questions you might have, and feel free to message me privately. I’ll add information here for other readers that may come across this thread, focusing primarily on the outdoors aspect of your questions:
I would describe Whitman as one of those hidden gems because of its location; if it were on the East Coast it would be well known, but as families there and in the Midwest can throw a rock and hit a dozen terrific LACs, there really isn’t a reason as to why they should or must look across the country at others. So it’s not really on anyone’s radar 
I’d describe the kids at Whitman as “smart and kind” - and yes, a lot of them are very outdoorsy and the outdoor program itself is fantastic, and they have a terrific rentals shop on campus for any and all outdoor gear at inexpensive prices (from kayaks, to tents, to backpacks and snowshoes, sleeping bags, stoves, etc.; plus all the clothing you might need such as hiking boots, rain jackets, and puffy jackets, gloves, hats, insulated booties, parkas and insulated winter pants, rain pants and gaiters and more). Plus there is the Bob Carson Outdoor Fund, which makes it possible for every student every year to go on a trip. The inexpensive rentals shop and the BCOF makes it possible to try so many activities that you wouldn’t have the opportunity to elsewhere.
Through the SSRA program (be sure to tap “load more” multiple times to see all the classes, which also change from year to year) my student (who’d only been on a climbing wall once as a little kid) has taken multiple indoor rock climbing classes and certification courses (Whitman has a fantastic climbing center), and they’ve become a certified climbing wall instructor. They also did a 9 day Wilderness First Responder class at the end of last year’s winter break, and are now a certified WFR as well.
Last fall they took a kayaking class that culminated in a 5 day sea kayaking trip through the San Juan Islands over October break. Another class in wilderness leadership led to a week long hiking, climbing, and camping trip in the canyons of Utah during spring break their first year. They also signed up for a day trip snowshoeing, and then another class in winter mountaineering that led to a long weekend snow camping trip!
They joined the climbing team their second year (which includes people of all abilities and levels of experience) and the climbing team hosts an annual weeklong trip to Red Rocks to camp and climb and go bouldering for a week of every spring break (and people can join for as few or many days as they like).
This is all to say that if you’re outdoorsy you’ll find your people, but also if you’re just curious about the outdoors and have neither the experience, nor the gear or any appropriate clothing to try things—Whitman is a wonderful place for you to try all those things out and have opportunities you couldn’t find elsewhere. (My student is on study abroad this fall, and wishes they could take the alpine mountaineering class this fall which culminates in summiting Mt. Baker!)
Walla Walla is a small town, but it punches above its weight being in the heart of wine country; it’s full of great food and people regularly visiting from all over and it’s a diverse community. It may superficially appear that Whitman and Grinnell are “both in small towns” but those are very different small towns, and the proximity to broader experiences (both city and outdoors) is quite different as well. We also looked at Grinnell and decided against it for being isolated in a way that didn’t feel comfortable for my student; it’s a terrific school! It just wasn’t the right fit for my student.
My student wanted small, seminar style classes with accessible faculty and they’ve found that. They also didn’t know what they wanted to major in prior to college, wanted a liberal arts education and room to explore, and at the end of sophomore year they declared a combined major in the sciences (being vague so as not to identify them!).
Editing to add: My student also wants to stay in the broader PNW after college, and the Whitman alumni network is strong here; when my student was in high school making their list of colleges, people from all professions were asking them what schools were on their list, and they’d nod and say “ah, nice!” to all the other choices (places such as Macalester, Grinnell, Carleton, etc.) but when my kiddo mentioned Whitman frequently their eyes would light up and they’d exclaim: oh, that’s a great school! And they would know someone who attended who is one of their favorite coworkers, or attorney, or scientist, or friend, or they were an alum themselves. Whitties are known as smart and kind “out here” and that’s a boon to students in ways that don’t show up on a chart.