Local forests in Colorado don't produce great woodworking lumber for the most part, but the cities do. I use a lot of urban lumber. There are several local small sawmills - sometimes I buy stuff they have cut, sometimes I find the logs and have them cut it. Logs are heavy, but I've gotten some great 8' logs over the years. You will have to pay attention to drying, but in Colorado a 2" thick plank will pretty much air dry itself in a couple of years - sometimes too fast. If you're willing to go this route, put your name out with local tree surgeons and landscapers - tell them what you are looking for and ask them to let you know when one is being cut down. The cash trees (black cherry, walnut) are hard to get, but you can get a lot of lesser known woods for next to nothing. In the past I've gotten apricot, plum, Russian olive, Siberian elm, orchard cherry, ash, burr oak, and maple for just the cost of sawing it.
For a while there was a guy who drove in once a month from Iowa and sold out of a small industrial unit. He had great rough sawn stuff at 1/2 the going rate at local retailers.
I've also had good luck with the "pallet" oak used to package metal buildings.
At any rate, it takes a while to ferret out the people who can help you get wood for less, but it's worth the time to find them.
Almost any source of cheap wood will require a jointer and a planer. If you source lumber locally, you'll probably want a 20" planer minimum. You'll probably also want to invest in a metal detector of some sort. Blades are not cheap, and the sawyer I use charges for hitting even one nail, barbed wire, or other metal. The good news is that I've only been bit by that once.