Several thoughts I started an hour ago before @Macgiver’s & @N9IWP’s posts.
For a guy like me in his same airplane that’s exactly what I’d do; ideally go over the rocks and the weather, if that’s impossible I’d go over the rocks and through the weather. But depending on what else I know about myself, my airplane, and the forecast & actual conditions out there, I may, as the proverb states, use my superior judgment to avoid the need for my superior skill and just go home.
Let’s assume we’re going …
It might take 70 miles of climbing to get above those mountains from his pass-hugging cruise altitude. So you need to know to start that climb 70 miles ago. If you wait until you’re close to the mountains the terrain rises more steeply than you can climb. And you may already have flown under teh higher clouds you don’t want to penetrate.
Our intrepid hero was certainly generally familiar with the area; he spoke of trying to fly through a couple of different canyons by name. But he didn’t start to climb early. So to climb to clear terrain he’d have needed to circle in place while climbing, or more efficiently, turned back while climbing, climb 2/3rds of the way to his altitude goal, then turn forward again to climb the last 1/3rd before he arrived at the high mountains. The 2/3rds - 1/3rd thing is a rule of thumb because climb angle decreases as you get to higher altitudes with weaker performance. The “turning back” part, even as a tactic to continue, doesn’t seem to have been part of his repertoire that day.
Snowy weather over mountains will almost always contain icing. Flight into known icing is prohibited in most lightplanes absent some fairly rare accessories. Flying into icing in an airplane not able to handle can also be rapidly fatal. Pretty quickly it won’t maintain altitude and now you descend unable to do anything about that. You might stall at a speed well above normal and spin in, or you might just let down smoothly and gently into a mountainside. Not good either way.
The only cure for encountering icing inflight in an airplane that can’t handle it is to turn back immediately. You can go from fine to screwed in a minute or two. And may not even be in true IMC yet while it’s happening. Climbing can sometimes be a cure for low-altitude icing or that occurring right at the cloud tops. But given how performance sapping icing is, and how marginally lightplanes climb at the 8, 10, etc. thousand foot level, climbing is rarely a practical choice in a lightplane.
In the particular case of the terrain along his route of flight the minimum safe instrument altitude is roughly 14,000 feet. More would be better to reduce near-terrain turbulence. Which altitude means you have to have supplemental oxygen on board. Both for legality and to keep your brain from going too stupid to fly. As a general matter aircraft of his type can climb that high if they’re light enough. He wasn’t carrying any people besides himself, so it’s reasonable to assume it would have been possible for the airplane to have gotten up to 14K+ feet. If his brain could.
If it was a sure thing there was sunshine above, say, 15,000 the smartest plan would be to climb up early in the sunshine, transit the mountains in the sunshine, then descend in the better weather we assume exists over the Salt Lake basin.
If the clouds were too high to climb over and he had an autopilot and he was willing to trust his life to it he could have climbed up to 14,000 well east of the high terrain, pointed it towards his destination and sat there hands-off clouds or no. That amounts to the bootleg IFR I mentioned upthread.
Ref @Magiver’s well-chosen comments in his first post above … If you meant fess up to ATC and have them offer this as a solution, sooner they’d say to turn back to the VMC you were in 50 miles ago over the lower terrain. Nobody is going to endorse “Hi ATC, I’m a VFR-only pilot and I want to try to penetrate 100 miles of snow showers over high terrain; can I have a vector through the worst of it to {destination airport} please?” Obviously all ATC can do is suggest. If he wants to climb into the clouds westbound after declaring that emergency they’ll watch and keep everybody else out of the way. Until the radar blip disappears.
The biggest failure of all is this idea:
A person who is not isn’t trained simply can’t fly instruments. It’s much harder than it looks. The balance system in your ears is telling you to ignore the instruments. It takes discipline and practice to get past that. It’s very similar to landlubbers getting seasick while sailors don’t. Your balance system has the power to take over your mind and stop your eyes from seeing.
All the videos, all the simulators, all the movies or chair flying in the world can’t prepare anyone for the reality of what that feels like within the autonomic systems of your body that are not subject to conscious control. You simply have to be desensitized by doing it. For hours and hours and hours. It’s not a god-like skill only the Chosen Few can attain. But there’s no shortcut. Hands-on practice is the only way. And if you don’t practice regularly, it gets too hard again.
I’ve often said flying isn’t all that difficult. But it is very, very, very real-time, like any other performance art. Stuff is thrown at you at whatever pace the machine and the outside world throws it at you. Your job is very literally to keep up or die trying. Unlike football, or musical performance, or acting, there is no timeout, no director yelling “Cut!”, no way to stop the music. It’s keep up the whole time or die along the way.
Research shows most VMC-only pilots lose control in IMC within 2 minutes. This guy would have needed to fly IMC in turbulence for between 45 and 90 minutes. Not gonna happen.
This mistaken belief that they can hack it is how flights into IMC happen. And end shortly thereafter.
The fact this guy was smart enough to not try to enter the clouds and in fact was doing his damnedest to avoid entering clouds probably would have let him survive identical weather over the Great Plains. In fact he probably had done just that several times & lived through it just fine.
What finally killed him, besides poor long term decision-making was rocks too close below, left, and right, and clouds too close above. Flight through any of the 4 is equally lethal for a VMC-only pilot. It appears he chose to strike the trees rather than climb into the clouds. Good last-ditch thinking, but better yet even just a minute earlier to have set down on the interstate or the median thereof.