Half a century ago, on April 25 1967, Colorado led the charge in ensuring the full range of reproductive care for its residents by becoming the very first state to pass a law legalizing abortion. Abortions had previously only been allowed in cases of rape or incest, or when the life of the mother was threatened.

Democratic State Rep. Richard Lamm thought he was committing political suicide when he introduced the bill to an overwhelmingly conservative and male-dominated state legislature. To his surprise, the bill passed, and he went on to serve three terms at the state’s governor.

The bill was signed into law six years before Roe v. Wade affirmed abortion as a constitutional right for all U.S. citizens.

Now, pro-abortion advocates are asking state lawmakers to honor Colorado’s reputation as a trailblazer in the fight for safe and legal abortions. In a letter, the Colorado Reproductive Health, Rights and Justice Coalition urged lawmakers against backsliding into a time when abortion care was out of reach for many women, particularly women of color and the economically disadvantaged.

Over the past few years, GOP lawmakers have made numerous unsuccessful attempts to pass legislation that would steer women away from making their own reproductive health choices and limit access to abortion.

This year, that included measures that relied on shaky science, like mandates for abortion providers to inform patients of a potentially risky abortion reversal method and describe fetal pain, for which there is no scientific consensus. Republican lawmakers also attempted to impose a 24-hour waiting period for abortions, and refer women seeking to terminate their pregnancies to anti-choice Crisis Pregnancy Centers.

These bills appear to be based on templates from legislation mills like Americans United for Life, which are attempting to restrict abortion access across the country. Last year, a report found that the organization was specifically targeting Colorado.

The letter argued that these recent efforts pose medical risks to women:

“Sham laws that impose medically unnecessary restrictions making abortion care more difficult to access and more expensive to obtain create obstacles where again some women are being put in desperate situations. We cannot allow this to continue. We cannot go back to women being injured, losing their ability to have children in the future or even dying because they cannot get a safe abortion from a licensed provider.”

The letter was signed by the Colorado Organization for Latina Opportunity and Reproductive Rights (COLOR), the ACLU of Colorado, ProgressNow Colorado, Planned Parenthood of the Rocky Mountains, the Religious Coalition for Reproductive Choice Colorado, NARAL Pro-Choice Colorado, and the Interfaith Alliance of Colorado.