Wednesday a group wanting to add a definition of marriage to the state constitution is expected to turn in the wording it wants to appear on November's ballot. If that's approved, they can start collecting signatures to get the measure on the ballot.
Coloradans for Marriage wants to define marriage as being between one man and one woman, a definition that already is part of state statute.
A group that opposes the measure has already begun to campaign against it, sending workers door-to-door in the Denver area.
Also at the state Capitol Wednesday, two Democratic lawmakers are expected to officially introduce a referendum that would allow same-sex couples to register as domestic partners and be treated the same as married couples under state law. If successful, that measure would also end up on November's ballot.