My husband writes for an outdoor magazine and we go backpacking/canoeing/kayaking/etc a lot for his stories. I would love to learn real photography (and maybe one day take pictures to go along with his articles). I had a few photography classes in college so I have a rough grasp of the basics. I would love a recommendation of what type of camera would help me to really learn about all the art that goes into photography, take good pictures and is semi-professional (but I imagine I will upgrade when I get better) and will not cost my entire life savings. The pictures I would take are of wildlife at a distance and landscapes.
The focus on outdoors use and specifically the combination of backpacking and canoeing/kayaking make this a difficult recommendation, I think, if you are focused on learning photography instead of just "taking pictures."
For backpacking, I'm not excited about the notion of taking a full-frame DSLR along. Back in the day I carried a film SLR a few times and it wasn't fun and proved cumbersome. The small size of the smallest DSLR may be an option, but I suspect a mirrorless camera would be a better choice -- giving you full control over a scene with a large-ish sensor and aperture that will let you control depth of field.
For canoeing in calm conditions, a Pelican case will keep the camera safe (when closed) and canoes are plenty stable to pull the camera out whenever you like without much fear of water damage. In a kayak, fitting a Pelican case (and keeping it secure) could prove very difficult, depending upon the type/size of your kayak; in other words, water damage could be a much greater concern, even in calm conditions. In rougher conditions, in either a canoe or kayak, you'll need a waterproof shoot-through case or a waterproof camera. However, with a waterproof camera you are giving up significant quality and control compared to the mirrorless or DSLR.
In other words, you've got a difficult decision here, and one camera may not suit your needs adequately.
Learning photography is much less about the equipment and much more about pushing yourself to learn. You can learn the basics of photography on essentially anything that allows for manual control of shutter speed, aperture, and ISO. Other aspects such as different focal length lenses, flash photography, and so on can be additional topics that one can learn once exposure is well understood.
If your husband works for an outdoor magazine, see if one of his coworkers has a used DSLR, advanced compact, or mirrorless camera that they could sell you inexpensively or even gift to you. That is where I would start, with equipment that is less then perfect and costs little to no money. If that doesn't work out, reach out to your own network. I can almost guarantee you know a photographer or two with used equipment collecting dust that they would love to pass on to an eager new photographer.
Once you have some equipment to start with, you will be challenged to learn how to use it despite its potential shortcomings or the fact that it is a few years old. You can focus on books , experiments, and the basics of photography vs 4k video, in camera HDR, and back button AF (all things that modern DSLRs provide but are not about learning photography for a beginner).
The problem here is that once you threw in "wildlife at a distance", you pretty much nixed most everything else except for dSLRs as well as the "starter" part of the equation.
Wildlife, especially fast-moving wildlife, is a very specialized and equipment-demanding type of shooting that causes some of us to blow thousands of bucks on a lens and a higher-end body just to get the fast tracking AF necessary to get a subject in focus and framed so it's not tiny. This is not by any stretch of the imagination a starter subject, and one you should probably work your way up to. [Sports would be the other similar subject]. So, if you give up National Geographic wildlife ambitions, then your question makes more sense.
I got fascinated with bird photography and most specifically bird-in-flight photography. I eventually came to realize my little 75-300 consumer-grade telephoto zoom wasn't going to cut it either on reach or AF speed, and blew $1100 on an EF 400mm f/5.6L USM lens. And eventually upgraded my entry-level dRebel for a prosumer XXD model (50D). I now jones for the 7DMkII. But that's a lot of money and outlay as a newb. And a lot of weight to haul around in a backpack.
So you have to weigh the drawbacks, and figure out which ones you're more or less willing to put up with. dSLR can do fast action and have the long lenses for wildlife shooting, but are big heavy beasts, and the long lenses are $1000+. Mirrorless cameras and lense are small and light, but there isn't yet a good array of wildlife lenses or the AF systems to capture them. Advanced fixed-lens compacts are smaller and lighter yet (and are cheaper because they're self-contained--you're not buying any more parts of the system), but have the limitations of the single lens.
The good news is that digital cameras handle outdoor photography the easiest. There tends to be plenty of light and subjects rarely move fast.
Any modern DSLR will do and something in the mid-range will allow you to learn photographic controls to exercise your creativity. There are also several weather-sealed models which will allow you to do outdoor photography in the rain or snow. This is particularly important for professionals as you may have to get images even if the weather is bad.
Something like Nikon D610 is great to start with and is relatively cheap for a full-frame. You can easily do with an APS-C camera which will cost less and make your lenses have a longer reach. In this case, I would recommend a Pentax K-3 (Original or II) which is freezeproof too.
Do not forget to allocated enough budget for lenses, at least the same value as the camera in general. It is also necessary to buy weatherproof lenses if you want the camera as a hole to be weatherproof. Start with at least too lenses, a general zoom for landscape (say a 16-50 or 17-55 on APS-C or 24-70 on full-frame) plus a long one for wildlife (something that reaches at least 300 or 400mm). Third party makers like Sigma make good ones for less than those of the camera manufacturer.
EDIT: Just a note why I did not recommend a mirrorless. While they do save weight, it is really not much when you consider the weight of a lens to reach distant wildlife. You will notice that mirrorless systems have almost no long telephoto lenses, usually maxing out at 300mm or less, depending on the system which means you will need a DSLR lens and adapter. Most of those have limitations too.
This is sort of a trite answer, but the best camera is the one you have with you, that you are most likely to use and/or have handy. There are all sorts of amazing photo essays and very artistic shots done completely on mobile phones, or with outdoors point-and-shoots.
I won't recommend specific models or even brands, but considering your outdoor activity, weight & volume are probably important factors. With that in mind, you might want to consider mirrorless cameras. They have all the control over exposure that DSLRs have, the same control that you probably covered in your photography classes, but have reduced weight and volume by eliminating the optical viewfinder, pentaprism, and mirror that SLRs have.
There are interchangeable lenses for these mirrorless camera systems, and because the mirrorless cameras have a smaller flange distance (the distance from the lens bayonet mount to the sensor) than DSLRs, you can use an adapter to mount just about any DSLR lens to many mirrorless cameras. (Note that you might not get autofocus or aperture control of the lens, depending on which lens is under consideration, and which specific adapter is chosen).
Some of these mirrorless cameras are every bit as good as more "professional" DSLRs, for certain shooting styles or intended targets. The ones you mention, wildlife and landscape (especially landscape), are excellent use cases for mirrorless systems.
(I am not shilling for mirrorless cameras. I don't own one. But I have shot with them, and I really like what they have to offer)
Your requirements are contradictory in every respect.
A ruggedized compact sports and active lifestyle camera will not have interchangeable lenses and will have a small sensor, even if you can get good optics.
But that's what I had on me when the "good stuff" gets sealed up in the storm bag, under Niagara Falls. I bought it for my in-laws to use and have a weather-proof (submersible, shock-proof) camera in the party.
I currently use both a mirrorless and a dSLR. Since you are interested in learning to really drive it, I recommend a dSLR. Specifically a APS-C ("crop") body that's cheaper to buy into and lighter than full frame; automatically more tele-photo (what you want) and you are not interested so much in full-frame's specific strength of low-light performance.
New low-end have the image quality of yesterday's mid-grade, but lose features like rapid burst shooting. You want one with two dials, so you can adjust both aperture and shutter easily: if looking low-end, check for that.
Get a major brand that has a mature and common selection of lenses. That is, Canon (EF/EF-S) or Nikon (not familiar with the lens types). You can retain the lenses as you upgrade, find uses lenses, and rent lenses.
For a specific recommendation of something I'm familiar with, look for a used Canon 60D. (When I sold mine, I found lots of them listed on eBay etc. probably for the same reason: upgrades to 70D for better video. So the "used" price is depressed but they are still good cameras. N.B. Michael Clark points out that the weather sealing isn't as good as other choices in the tier.) Future readers: the point is that at any given time there may be some less-than-current model available for an especially low price.
Also important: plan a way to carry it. A strap to keep it from swinging on your chest while hiking, and cover it against splashes and sudden light rain.
When you see something you like, check dpreview for details on how easily the settings can be manipulated and how it performs, as well as weight.