Colorado Gov. Bill Ritter on Thursday signed into law House Bill 1260, a measure that allows gay and lesbian couples and other unmarried adults to establish sweeping legal rights for each other — including inheritance, the ability to make medical decisions and hospital visitation rights.

Groups representing gays and lesbians, senior citizens and low-income residents cheered the governor’s support for the Designated Beneficiary Agreement Act, which goes into effect July 1.

“We are excited that this new, low cost, and convenient estate planning tool will become a reality for all Coloradans,” said Equal Rights Colorado spokeswoman Mindy Barton in a statement. “These issues are a matter of self-determination and we are glad that the Colorado State Legislature and Governor Ritter have recognized these essential rights.”

The law, sponsored by two of the state Legislature’s only openly gay members, Sen. Jennifer Veiga and Rep. Mark Ferrandino, both Denver Democrats, allows any two unmarried adults to designate each other as beneficiaries by filing a form with a county clerk. The form bypasses a patchwork of contracts, wills and powers of attorney they would otherwise have to execute with a lawyer’s help. The law also adds several rights — such as the ability to file a wrongful death lawsuit on a partner’s behalf — which couldn’t previously be granted contractually under Colorado law.

“Today is a good day for Colorado and all Coloradans,” Ferrandino said in a statement. He called the law “a good step towards providing equal treatment under the law for all of Colorado’s families.”

The bill, which passed the Legislature with only a smattering of Republican support, drew criticism as an attempt to establish “marriage light” from Sen. Kevin Lundberg when it appeared before a Senate committee. The Larimer County Republican blasted the bill as an end-run around voters, who defeated a ballot initiative to establish civil unions for gay and lesbian couples in 2006.

The Colorado Senior Lobby disagreed with Lundberg’s characterization of the proposal and praised the governor Thursday for signing the bill. “This will help ensure that senior citizens who have worked a lifetime to earn benefits can keep them while designating someone to look after their affairs if they are in a medical crisis or at the end of their life,” Senior Lobby spokesman Mike Drake said in a statement.

While the law fails to establish all the rights that would have been available to gays and lesbians under civil unions, it does grant many that bring same-sex couples closer to legal recognition.

“This is an important step toward equality, and it will provide lesbian and gay couples in Colorado, and their families, with important, tangible protections that are needed right now,” Joe Solmonese, president of the national gay civil rights advocacy group Human Rights Campaign, said in a statement.

The specific rights spelled out in the legislation include: