Your experience was not unlike a lot of other folks who have never flown mountains. Johnson Creek is pretty tame compared to some of the others and is a good place to start.
High altitude Mountain strips are where I grew up flying, to me it's second nature. On the flip side of the coin, I have flown into big metropolitan airports where they had extensive flight training (a virtual hornets nest)with foreign student pilots who spoke very broken english....not that's scary. I'll take the mountains anyday over that.
Some of the strips we have flown are closed now and some were never officially listed anywhere. It's important to use the ones still open or they may be closed in the future as well, for lack of interest.
Many people become so intimidated by the mountains the first time they become week kneed and start making excuses why they can't continue on....something is wrong with their aircraft. Riggings wrong, somethings vibrating etc. Usually a flat lander with big tires and all the Alaskan mods on their aircraft. Instead of asking for help they go on and tell you a lame story how they have thirty some odd years flying experience and how they did this and that. Don't mean squat.
One of the most important things to keep in mind for flatlanders who are used to flying the horizon is when they get down below the ridges and varying angles of slopes they can get pretty screwed up on visual cues.
A lot of people will try to fly early mornings and late evenings to avoid the thermals. Early morning is best if your flying in. If you fly in to close to dusk in the evening, at altitude it will seem you have plenty of light, but once you drop down below the ridges you'll wonder how it got so dark so fast. Making your landing a little more challenging.
If you need to tighten a turn low and slow in the hills, you better drag on flaps or you may not complete the turn.
