Amendment 71 would require "a more expansive geographic distribution of those signing petitions to put such a measure on the ballot—and then requiring 55 percent of voters to approve it instead of a simple majority," reports The Denver Post. "Specifically, signatures would have to be collected from each of the state’s 35 senate districts in numbers equal to at least 2 percent of the registered voters in each district."
Anti-fracking activists tried, but failed, to get two other measures on this year's ballot. One would have banned new oil and gas facilities within 2,500 feet of an occupied building; the other would have given more power to local governments to restrict fracking. Petitions are required to have 98,492 voter signatures.
Colorado residents tried to get similar measures on the 2014 ballot. That move was derailed by Democratic Gov. John Hickenlooper, who has said he would do whatever it takes to beat anti-fracking initiatives. In May, the Colorado Supreme Court ruled against Front Range towns that wanted to pass anti-fracking measures, saying state law trumps local ones.