In the state of Colorado, you can buy marijuana for recreational use as long as you are over the age of 21. You need to bring a valid ID (cannot be expired) or if you are a foreign tourist you need to bring your passport.
You also need to bring cash with you because it is still against Federal Law to use marijuana so they are unable to get banks to allow them to process debit and credit cards.
They have all sorts of products to smoke, eat or apply to the skin.
Remember that you cannot leave the state with any marijuana products.