Very interesting discussion, much food for thought. Unfortunately, in CO, and in Utah, I have been told, it is illegal to catch rainwater or use greywater. And it would be very hard here to find enough native crops to make a meal. A friend has shown us some weeds and bushes that might contribute salty seeds to season a stew, and I know there are serviceberries and Pinyon pines at higher elevations, but those are mostly now inside the National Monument, and off-limits to harvest.
At my location, the only"natives" I know about are things like sagebrush and rabbitbrush and a few kinds of wildflowers. We have patches of prickly pears, but they only grow about 4-5 inches high, are very thorny, and have never fruited, though I have seen a few flowers in a wetter than normal year. And of course, the deer, and pronghorns, and elk, and rabbits and voles and mice and sparrows, none of which we could live off of, either because of limited numbers and hunting laws, or they are too tiny to be worth the effort to catch and clean them. But the small ones sure make it a challenge to grow anything, especially the sparrows, which fly around this small town in a huge flock, wiping out anything they can find. I tried covercropping, and they just kept eating all the seeds before they could sprout.
I am learning to love the high desert, and see beauty in the landscape, the beautiful sunrises and sunsets, etc, but it is a challenge to learn what is adapted and how to grow anything we can eat.
My "advice" is: keep trying. Try all the ideas that seem remotely possible, and keep adding organic matter and planting anything that might survive in your climate and soil. Observe what others have growing, and keep learning.
For example, I have seen, in nearby yards, wild roses, rhubarb, cherry and apple and apricot trees, Nanking cherries, sumac, strawberries and raspberries, lilacs, and clovers. I have added a few others, like Siberian pea shrub, and bush cherries, and Egyptian walking onions. By combining these and similar hardy plants, I have been able to create a Mini-food-forest in my yard that is starting to fill in and provide some shade and wind protection, leaves for mulch, and even some food. But it takes time to observe and study and prepare the ground, and get plants established, etc. And, it takes a lot of space, and mulch, and compost, etc, to really be able to grow more than just enough food for occasional snacks or seasoning.
I have also learned, from Caleb Warnock, author of Backyard Winter Gardening, to use low framed beds (using 2x4s or 2x6 boards) with cold frame covers, to grow food outside my growing season, which is barely 90-100 days from killing frost in June to 1st frost in Sep. So, I know if I want to eat all year, I have to use a combination of methods.
But the most important piece of advice is Never Give Up. Even when it is hard, if we keep learning, we can help ourselves and others around us if times get even harder.