Picacho Peak History: The Battle of Picacho Pass and the Peak Along I-10

Picacho Peak is the sharp, hooked summit you see from I-10 between Casa Grande and Tucson, and in April 1862 the desert at its base saw the largest Civil War clash in Arizona. A Union cavalry patrol from California ran into Confederate pickets there, and three Union soldiers were killed.

I drive past Picacho Peak every time I head to Tucson, and I still look up at it. Most people speeding by have no idea soldiers fought and died in the brush below it.

A Landmark Travelers Have Used for Centuries

Long before the freeway, people used this peak to find their way. Arizona State Parks says it has served as a landmark since prehistoric times, and one of the first written records of it comes from the Anza Expedition in the 1700s. Around that same time, Father Francisco Garcés called it Cerro de Taca, borrowing the O'odham name for the mountain.

The name we use today is a little funny. "Picacho" already means "peak" in Spanish, so Picacho Peak is basically "Peak Peak." Nobody seems to mind.

In 1846 the Mormon Battalion built a wagon road through Picacho Pass. Gold seekers heading to California in 1849 used it, and by the late 1850s the Butterfield Overland Mail was running stagecoaches through the pass, with a stage station near the peak. That road is the reason two armies ended up here.

How the Civil War Reached the Arizona Desert

When the war began, the Butterfield line shut down. In late February 1862, roughly 120 Confederate cavalrymen rode into Tucson from Texas and claimed it as the capital of the western district of Confederate Arizona Territory. Captain Sherod Hunter was the officer in charge of that force.

The Union answer came from the west. Colonel James Henry Carleton organized the California Column, about 2,000 volunteers, and moved them east toward Fort Yuma and then up the Gila River. The Confederates kept small groups of lookouts, called pickets, along the old stage road to watch for them.

April 15, 1862: The Skirmish at Picacho Pass

On April 15, 1862, Lieutenant James Barrett of the 1st California Cavalry was leading a small patrol of about a dozen troopers and a scout. Near Picacho Pass Station they found a Confederate picket led by Sergeant Henry Holmes, hidden in the mesquite.

Barrett ordered his men to ride into the thicket in single file without getting off their horses. The first Confederate shots knocked several men from their saddles. Three Confederates surrendered, but Barrett was shot in the neck and killed. The fighting went on for about an hour and a half in the brush and dry washes before the Union troopers pulled back.

Barrett and two enlisted men, George Johnson and William S. Leonard, were killed, and three more troopers were wounded. The two privates were later moved to the national cemetery at the Presidio of San Francisco. Barrett's grave is said to be somewhere near the railroad tracks, unmarked, and its exact spot has been lost.

What Happened Next

The skirmish slowed the Union advance, but it did not stop it. The Union troops fell back to the Pima villages along the Gila and built a post there called Fort Barrett, named for the fallen lieutenant. Hunter's men soon left Tucson, and Union forces marched into the town without a fight. The Confederates retreated toward Texas later that year.

In 1928 a monument was put up listing the names of the three Union men killed. Today the skirmish site and the remains of the Overland Mail stage station at Picacho Pass are on the National Register of Historic Places.

Picacho Peak State Park Today

Local communities, including Coolidge, Eloy and Florence, petitioned for a park here in the early 1960s. The state bought its first land in 1966, and Picacho Peak State Park opened on Memorial Day, May 30, 1968. The opening ceremony honored the men killed and wounded in the 1862 fight.

The park sits right off I-10 at Exit 219, near Eloy. A few things I tell people who visit:

• Memorial Loop: a short, wheelchair-accessible 0.1-mile loop with signs that tell the story of the battle. This is the easy way to connect with the history.
• Hunter Trail: 1.6 miles one way to the summit and rated difficult. The upper part uses steel cables on exposed rock. Bring gloves and plenty of water.
• Wildflowers: after a good winter rain, Mexican gold poppies can light up the slopes in spring.

Coming up soon, Arizona State Parks lists an American Civil War Encampment at the park on November 21 and 22, 2026, from 9 a.m. to 3 p.m., with a ranger talk on the Battle of Picacho Pass and a weapons demonstration both days. The park also lists ranger-led "Soldier's March" walks about the battle on various Saturdays from December 19, 2026 through March 13, 2027. Check the Arizona State Parks site before you go.

Living Near Picacho Peak

Eloy sits right next to the park, and Casa Grande and Arizona City are a short drive away. If you are curious about that part of Pinal County, my Moving to Eloy, AZ guide and Moving to Casa Grande, AZ guide are good places to start, and you can browse homes for sale in Eloy. For another Pinal County story, read about Florence and the courthouse clock stuck at 11:44.

Questions people ask

What happened at Picacho Peak in the Civil War?
On April 15, 1862, a Union cavalry patrol from California fought Confederate pickets near Picacho Pass. Lieutenant James Barrett and two of his men were killed, and three Confederates were captured.

Is the Battle of Picacho Pass the westernmost Civil War battle?
It is often called that, though some historians point to a smaller clash at Stanwix Station, farther west along the Gila River. Arizona State Parks describes Picacho Pass as the largest Civil War clash in Arizona.

What does "Picacho" mean?
Picacho means "peak" in Spanish, so the name Picacho Peak repeats itself. An earlier name was Cerro de Taca.

Where is Picacho Peak State Park?
The park is in Pinal County along I-10 at Exit 219, between Casa Grande and Tucson, next to Eloy.

Terry Day, REALTOR®, DeLex Realty, 10115 E Bell Rd, Scottsdale, AZ 85260.