Two Colorado measures aimed at limiting fracking failed to get on the November ballot because they lacked enough valid signatures, the state announced Monday.

The two initiatives would have asked voters to approve changing state law to allow municipalities more control in allowing or banning fracking and instituting a 2,500-foot setback from any building for oil and gas operations.

Colorado law requires 98,942 valid signatures for an initiative to make it onto the ballot. Both Initiative 75, which would have changed state law to allow bans, and Initiative 78, which would have required the setback, had more signatures than required, but not enough of those signatures would have been valid, according to a random sample taken by the state.

Secertary of State Wayne Williams said some of the signatures for Initiative 78 may have been forged.

"For No. 78, the petition-processing team identified a petition section that contains several potentially forged signature lines," Williams said. "Although the secretary of state does not conduct signature verification when reviewing petitions, our office has referred the questionable section to the attorney general's office for investigation."

Local control of fracking has been a big issue in Colorado in the last year.

Voters in two towns passed bans or moratoriums on fracking. However, the Colorado Supreme Court ruled that they violated state law.

While campaigning in Colorado, both nominees for president — Democrat Hillary Clinton and Republican Donald Trump — expressed support for municipalities passing fracking bans. An adviser to Trump said last week that the real estate mogul had changed his mind, but Trump has not spoken on the issue directly.