The measure passed by state lawmakers this year would ban nearly all abortions in South Dakota and is intended to prompt a court challenge aimed at overturning the 1973 Roe v. Wade ruling that legalized abortion in the United States.
About 1,200 volunteers in 138 South Dakota communities collected signatures for the South Dakota Campaign for Healthy Families, said co-chairwoman Jan Nicolay.
"We did this with volunteers, not paid people, and I think that's even more significant when you look at that," Nicolay said at a news conference in Sioux Falls on Tuesday morning before the group headed to file the petitions with Secretary of State Chris Nelson's office.
Nelson's office will have to verify that the petitions contain the required 16,728 valid signatures to place the question on the November ballot.
Leslee Unruh, a Sioux Falls anti-abortion advocate who lobbied for the ban, said she believes South Dakotans will do what is right to protect women and children.
"The people certainly will make it known how they feel," Unruh said. "And I believe we are a pro-life state."
South Dakota Rep. Roger Hunt told CBS affiliate KELO-TV in Sioux Falls that it is the public's prerogative to call for a referendum on the law. "This is an important right that our people have. I sometimes call this the fourth branch of government."
But Hunt agrees with Unruh that the statewide vote will probably support the ban. "South Dakota has been electing pro-life legislators for years and years," he told KELO-TV. "They've been electing a governor who's a pro-life governor. All that tells me is the fact that the voters in this state are by in large, by a good majority, pro-life."
Opponents of the law argue it is too extreme because it provides no exceptions for rape, incest or the health of the mother.
Supporters have pointed to a section of the bill that allows emergency contraceptives to be given to rape and incest victims.
Dr. Maria Bell, who served as vice chair of a 17-member abortion task force, said emergency contraception is not a valid option for victims of rape and incest.
Unruh said there have been questions about whether signatures were collected properly, and supporters of the ban plan to comb through the names to make sure they are valid.
She said supporters of the abortion ban are getting ready to launch the "Fleet for Little Feet," a recreational vehicle that is being used as a medical and counseling center to help rural women facing unexpected pregnancy. The bus also will park outside malls, college campuses and the state's abortion clinic in Sioux Falls.
Nicolay, a former state legislator, said residents who signed the petitions told her that government had overstepped its boundaries and they did not want people telling them and their families what to do. Others were opposed to not having exceptions for rape and incest and felt the law was too extreme, she said.