Felipe Nerio Espinosa was born around 1827—some accounts say 1836—into a poor Hispano family in El Rito, Rio Arriba County, in what was then Mexican territory. His parents, Pedro Ignacio Espinosa and Gertrudis Chávez, raised him alongside his brother Vivian in a struggling setting marked by discrimination. After the 1848 Treaty of Guadalupe Hidalgo, the family found themselves under U.S. jurisdiction. They faced land loss and displacement, tensions mounting with Anglo settlers. Felipe was reportedly literate, devoutly religious, and part of the Penitentes, a Catholic brotherhood known for self-flagellation rituals.

In the late 1850s, he and Vivian moved to San Luis Valley, southern Colorado. Facing destitution, Felipe turned to crime—freight robbery and horse theft. He once brutally dragged a teamster tied under a wagon tongue for miles. Their home was attacked by U.S. forces posing as army recruiters, leading to a violent gunfight that ended with their farmhouse burned and property confiscated.

Felipe and Vivian Espinosa’s descent into murderous desperation unfolded against the raw backdrop of the 1860s Colorado Territory, where frontier justice and deep-seated injustice collided. In March 1863, their transformation from low-level bandits to infamous killers began in Sawmill Gulch, near modern-day Cañon City. Their first known victim, Franklin Bruce, a sawmill worker, was shot dead in cold blood. Not long after, another man—Henry Harkens, a lumberjack—was found inside his cabin, a bullet through the forehead from a Colt Navy revolver. To make the atrocity even more chilling, Harkens’s skull was split in half with an axe, his brains scattered across the floor.

As spring wore on, bodies began to surface near Fairplay and South Park. Victims were often ambushed in quiet mining camps and left grotesquely mutilated—one with a bullet-marked forehead and a twig crucifix embedded in the wound, another with their head crushed under a rock. Newspapers began calling the perpetrators the “Axemen of Colorado.” The tone of the coverage betrayed widening fears:

In late April, a fateful encounter nearly unraveled the Espinosas’ anonymity. A lumberman named Metcalfe was shot in the chest while driving through California Gulch. Miraculously, a copy of the Emancipation Proclamation in his jacket pocket deflected the bullet. The escape gave authorities their first eyewitness. A posse led by Captain McCannon tracked the brothers to a campsite. In the ensuing shootout, Vivian was killed. Felipe appeared but managed to flee into the forest. 

That summer’s lull gave rise to rumors and fear. Some settlers said they’d come home to find their houses burned and families butchered—fuel for grudge‑laden folklore. Others cited land dispossession and cultural erasure after the Mexican–American War as motivations for the Espinosas' spree.

With Vivian gone, Felipe recruited his teenage nephew José and resumed killings in autumn. One bizarre ambush near present-day La Veta involved a Hispano woman being tied up and abused—her Anglo driver escaped and alerted Fort Garland authorities. 

The U.S. Army sent for almost-legendary tracker Thomas Tate Tobin—known for tracking a grasshopper through sagebrush and having connections with Wild Bill Hickok and Kit Carson. Guided by magpies circling overhead and a thin column of smoke, Tobin found the outlaws cooking ox meat near a remote camp.Tobin raised his gun and fatally hit Felipe in the chest; José fled and was also shot. Felipe crawled to a tree, attempted to fire but failed, and then Tobin and soldiers finished him off with a volley.

In a grim final gesture, Tobin decapitated both bodies and returned to Fort Garland with their heads—either displayed in the newspaper office or preserved in alcohol.