Gov. Jared Polis plans to rewrite Colorado history during a ceremony to sign an executive order Tuesday at 11 a.m. at the state Capitol.

His signature will “rescind proclamations by Territorial Governor John Evans that shamefully targeted and endangered the lives of the American Indians,” the governor’s office told reporters Monday evening.

Evans was Colorado’s second territorial governor, holding the office during three years of the Civil War, from 1962 to 1865. He is the namesake of Mount Evans and the town of Evans.

He also has a blemished past fighting the natives on the new frontier. He resigned after being held accountable for the Sand Creek Massacre, when cavalry under his order slaughtered a tribe of peaceful Indians, mostly women, children and old people.

At the time, fear was rampant in Denver that the emerging frontier would be overrun by Indians.

Polis will be joined by Lt. Gov. Dianne Primavera, members of the Southern Ute, Ute Mountain, Cheyenne and Arapaho tribes, and other members of Colorado’s American Indian and Alaska Native communities.