(1) You said that none of your relatives live in CO. Do you have relatives living in another state? If so, can you afford a bus ticket to get to their place? If not, perhaps one of your friends could lend you enough money for the ticket?
(2) Contact a school counselor and ask for their advice. Even if you already graduated last year from high school, you probably know the counselor who works at your old school.
(3) Apply for jobs in which room & board are included. For example, perhaps some mountain resorts and lodges in CO are hiring waiters, kitchen staff and other service personnel. I also know that some people your age are hired by logging or tree planting companies (that replant logged areas of forest). Since they work in remote areas, the companies provide food and lodging for their employees. You could also join the military if that's a path you're willing to go down.
(4) If all else fails, you can contact a local branch of the YMCA or YWCA; they can provide temporary shelter for young people in your situation. It could be a temporary solution until you can find steady work (or join the military).
EDIT: There is another option: crowdfunding. You can use GoFundMe or some other crowdfunding website to raise money to help meet your basic expenses like food and shelter until you can land a job and get back on your feet. Going homeless is a situation that would certainly qualify.
https://www.gofundme.com/questions/
If you set up a page on the site, you can share it with your friends and classmates to ask them for a bit of help. Begging for money is never fun, but in an emergency like this one, sometimes it's unfortunately necessary.
EDIT2: According to the GoFundMe website, "US users may also request a check" when it comes to withdrawing the money you have raised.
https://www.gofundme.com/questions/
You can cash a check without having a bank account (though unfortunately sometimes they will deduct a "transfer fee" if you do so).
http://money.usnews.com/money/blogs/my-money/2015/02/20/how-to-cash-a-check-without-a-bank-account
EDIT3: Request that your check be sent "general delivery" to the town/city in which you reside. You will have to visit the post office and request to receive the mail by name.
https://en.wikipedia.org/wiki/Poste_restante
Anyways, if you have further questions regarding GoFundMe and how to receive your money, it's probably best to contact them directly so that you can get the most accurate information. I haven't actually used this service myself; I just know of others who have.
http://support.gofundme.com/hc/en-us/articles/204457248-How-do-I-withdraw-my-money-US-Canada-
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