Yosemite over Yellowstone any day! Though you do see more wildlife in Yellowstone. I love half dome and you have done well depicting it, though I always think of her flat side as her face so I would want to leave more room for her to look into. I am sure there are others who will disagree and it has more to do with how I view the formation than anything. These would be a little easier to evaluate full size, but from the thumb I think the B&W could use a little more contrast in half dome to make her stand out from the background a little more.
Where were you standing when you took this?

JoBear, no I don't have the Lee polariser though I have been very close to buying one. The cost is very high and putting me off and I do have a Hoya polariser which is excellent. The only downside to the Hoya polariser is that it came apart when I was using it with the Lee system and the filter holder with filters fell off - fortunately into a rock pool and it missed the rocks so the Lee filters were fine. Amazon very kindly replaced the polariser so no harm was done.

Not sure what you mean in the last part of your post.

The "dreaded X" to which you refer is called by the folks at Singh-Ray the "Maltese Cross" - it happened to me with their vari-ND filter on my Fuji X-T1 though I had no issues with my various Nikon DSLRs (D200, D700, D600) over the years. Apparently it's specific to the size of the photo sites and has to do with constructive/destructive interference in those cases. This is because a variable ND filter is essentially two stacked (circular) polarizing filters which, when at 90 degree angles to each other, cut out almost alight (theoretically it would be all the light, but in practice it becomes 8 or 9 stops worth).

As I understand it, the Lee filters are not variable at all - they are pure ND filters (as are the standard ND filters from other filter manufacturers. So there should be no problem with the Lee filter - I have been using a number of (non-variable) ND filters without issue on the Fuji since there is no polarizing filtration involved with those - they are essentially just "really dark sunglasses".

John, you are in luck in your search. There are many different types of training available today. You will probably hear from people here who have used one or two and like them enough to promote to others. For starters I will recommend CreativeLive.com. Video training in many facets of photography. They offer an instructor named John Greengo who has created a series of videos designed to quick teach several different camera bodies. Most of the more widely used bodies can be found here. There are several courses in the more directed area such as landscape and national parks, boudoirs, babies, street, you name it, they teach it. Their menu is quite sufficient to get your feet wet, and then some. Also on my preferred list is Lynda.com (Notice the Lynda spelling). This site charges by the month and offers lots of different subjects. You pay a flat fee and use it as much, or as little as you wish.

Both sites offer courses in Lightroom, Photoshop, Aperture, and other photo programs. Each site allows the user as much time as is required. The instructors on both are very good at what they do. Some will relate to students in different ways, but most are worth your time and effort. Each site continues to develop new courses and builds entire programs designed to allow the student the total learning package.

There are many other site available. Others here at the Hog can and will fill you in on them. Good luck in you quest, it can be very rewarding.