How do you cook pinto beans at high altitude?

I can answer this, living in Colorado Springs, Colorado, (5000 ft plus) for the last 18 years and making pintos once a month, for as long! Hint, SOAK, SOAK, SOAK! Also, DO NOT add salt till the very end! I soak overnight, drain and clean (especially before soaking, to fetch any missed stones and pebbles). I cook in cast iron kettle, avoiding aluminum, with a kettle of boiling water on the side, to add to beans, as the water reduces, every 1/2 hour or so, for maybe 2 1/2 to 3 hours total, until they start to thicken. I then add thick cut yellow onions, Hamhocks (smoked), black and white pepper and finally the salt. No other spices for me. To keep them vegan, I avoid hocks and just add a cup of sunflower oil, about 2/3 of the way into cooking time. Mmmmm, I'm gonna make some now!