Sorry but I don't think you will have much success in a dry climate without some means of irrigation or regularly carrying in water. If no weeds, high grass or dense brush grows there, there is a good reason for that. Its because you live in what is basicly a semi-desert. Also you wrote "i'm not going to do much preparation or maintenance" Without very thorough preparing of the spot, you are certainly not going to get much result. Preping a spot takes time and effort and most of all hard work (digging). That is the number one most important factor in success. At a min, you should add in lots of organic compost and water crystals to make the most of the minute amount of rain that you get in Co. Too bad you can't just toss some seeds on the ground in a barren, no growth, dry as a bone rock hard area on the side of a steep slope and get some good bud from it. If it was that easy, people would not be getting $300 / Z for good smoke. Don't mean to rain on your plans but just being realistic.

good luck