We hired a neighbor to build several raised beds for us, with hardware cloth fastened to the bottom to exclude the pocket gophers, and to fill them with organic horse manure compost mixed with our native soil.
We've been experimenting with which vegetables and herbs grow best at our altitude, and so far we have had great results with short-season varieties of
Summer squash (pattypan, zephyr, and zucchini)
Cool-climate herbs like parsley, tarragon, winter savory, dill, and borage
French beans and snap peas
Greens, including leaf cabbage, chard, arugula, kale, and a variety of lettuces
We grow some shorter-season tomatoes (Stupice and cherry tomatoes) and basil in our greenhouse. We also have access to an organic farm only half an hour away (at much lower elevation) that grows amazing sweet peppers, eggplant, and tomatoes, so we pick those at the end of the summer and don't bother to grow them in the mountains. And we supplement our produce all summer with additional varieties from the nearby farmer's market.
We've planted some berry bushes, rhubarb, and asparagus as well, but since it takes a few years for them to establish well enough for harvesting, we haven't gotten to try them yet!