Ballot measures have been used in the U.S. state of Colorado to place new legislation, those recently passed by the Colorado General Assembly, and constitutional amendments on the ballot for a popular vote. Colorado has had a system of direct voting since gaining statehood in 1876. The state has three types of ballot measures that can be voted on in a statewide election: initiatives, referendums, and legislatively referred measures. The first successful citizen-initiated measures were passed in 1912. Since that time, ballot measures have played a major role in Colorado politics. After Denver was awarded the hosting rights to the 1976 Winter Olympics, citizens moved to block funding the games with a referendum in 1972. A 1990 ballot measure instituting term limits for many elected officials helped galvanize a nationwide movement for term limits, and 2000 Colorado Amendment 20 legalized the medical use of marijuana (greenhouse pictured). That measure was followed by full decriminalization with 2012 Colorado Amendment 64, and the decriminalization of psilocybin mushrooms in 2022. (Full list...)