Where to buy it
Anyone 21 and over with a valid ID (state-issued ID, a valid passport or Native American or military ID) can shop at a recreational dispensary. Some medical dispensaries will only serve state-registered medical marijuana patients, so check before going in.
Most of Colorado's largest towns — Denver, Boulder, Fort Collins, Pueblo — allow recreational marijuana sales, but not all of them do. Colorado Springs and Grand Junction are notable holdouts. In fact, the majority of local governments in Colorado, many of them small towns or rural counties, still ban marijuana stores, so make sure the town you're visiting has the good stuff before getting too comfy. While some mountain resort areas do not allow pot sales, towns nearby them do.
Important note: Although not technically required by law, virtually all dispensaries (and bars) will only accept horizontal IDs, in order to make sure they're not serving underage customers. How to buy it
Colorado residents and visitors alike (21 and older) may purchase and possess up to one ounce of marijuana at a time. Medical marijuana patients may purchase and possess two ounces of marijuana at a time. Possession laws are the same for all types of retail marijuana, but dispensaries may only sell 8 grams of concentrates and edibles containing no more than 800 milligrams of THC.
Dispensaries are open during the COVID-19 pandemic, but some stores are confining sales to curbside or to-go pick-up, so check before you go. If you are allowed in, a mask will be required. Most pot shops are still unable to accept payment online, though, because of the whole Schedule I thing, so have your cash ready, as many waiting-room ATMs are currently unavailable.
Recreational marijuana delivery is currently illegal in Colorado, although several Boulder dispensaries deliver for medical marijuana patients.
Where to smoke it
Open or public consumption of marijuana is illegal in Colorado and can result in a $100 citation. Places you cannot consume: transportation facilities (trains and bus stations, for example); parks; music, sports and amusement venues (not that many of those are open). You cannot smoke marijuana — or anything else, for that matter — indoors in any public facility, including restaurants, theaters or office buildings. Although a new state law allows businesses to apply for marijuana consumption areas, only two cities (Denver and Colorado Springs) currently license such venues, with fewer than five between them; there are several private consumption-friendly clubs and event venues, though. See a list of all those places here...but fair warning: Their operations could be affected during the COVID-19 pandemic.
The majority of hotels and home rentals in Colorado ban smoking of any kind, but not all of them do, so check with your host or the listing agent. We've also compiled a list of marijuana-friendly lodging options, though some of them have closed during COVID-19.
National and state parks
Colorado state parks ban marijuana consumption, with some areas also banning marijuana possession. National parks, such as Rocky Mountain National Park and other forests, hiking trails and camping areas in Colorado, operate under federal laws, so all marijuana is banned in these areas. Some national park rangers are friskier than others, so plan ahead if you intend to take marijuana along on a hike.
Traveling with it
Driving while stoned is still very illegal in Colorado, and can result in drugged-driving charges similar to alcohol DUIs. The state limit (though proven inaccurate to measure intoxication) is 5 nanograms of THC per milliliter of a driver's blood, but marijuana affects all of our intoxication and blood-THC levels differently.
Denver International Airport prohibits the possession, use, display and transfer of marijuana on its property, but charges and citations for marijuana possession at the airport are rare. Other Colorado airports have similar rules (and even marijuana disposal bins), though some are less stringent than others.
And if you're driving, be careful out there: Some neighboring states love to pull over cars with Colorado plates.