A group pushing to legalize marijuana in South Dakota at the ballot box still needs thousands of signatures as the deadline to file a petitions nears.

South Dakotans for Better Marijuana Laws for months has been circulating petitions that would force the Secretary of State to place a question on the November ballot, asking voters if the state’s prohibition on recreational marijuana use and sales should be repealed. And though it touted having as many as 20,000 signatures collected in a recent press conference, the organization’s campaign manager now says the group’s efforts are at risk of falling short.

“There are a large number of petitions out there that haven’t come into our office yet,” said Matt Schweich, director of SDBML. “But we feel a little nervous and we need people to know that we need them to sign, volunteer and work.”

While the total number of signatures exceeds 20,000, Schweich said an internal validation process recently revealed only about 13,500 of them are valid. About 17,000 registered voters must sign the SDBML’s petitions to force a vote.

To make a final push, SDBML has drive-thru signature drives planned in Rapid City and Sioux Falls in the coming weekends, and is adding more volunteers and staff. [Read more at Sioux Falls Argus Leader]