Anza-Borrego State Park: Calcite Mine Palm Wash Loop: Feb 2019

Updated: Feb 28

Hike distance; 7.1 miles


California’s largest state park, Anza-Borrego, protects 600,000 acres of desert terrain, including dramatic badlands, cool palm oases, twisting slot canyons, and cactus-studded slopes. This desert preserve pairs the name of famed Spanish explorer Juan Bautista de Anza, who crossed the desert in 1774, and the Spanish word for sheep (“borrego”)—referring to the region’s native bighorn sheep. The park’s striking landscape is in continual flux from flash floods, seismic action, and erosion. This map shows the location of this gem of a state park in relation to more commonly known locations in southern CA.

The calcite mine trail is accessible right off S22 around mile marker 34. We started the hike by descending from S22 into the Palm Canyon Wash and then we began a gradual climb along the far side of the wash before heading NW up the hill (marked in yellow).


The trail continued on a plateau that offered great views of the surrounding hills.

Hiking Calcite Mine Palm Wash Loop at Anza-Borrego State Park
Hiking Calcite Mine Palm Wash Loop at Anza-Borrego State Park

The trail followed a road that had been used during the WWII when calcite was mined here; now there are only a few traces of the road remaining.

Following an old World War II road to Calcite Mine Palm Wash Loop at Anza-Borrego State Park

Patches of desert lilies lined the trail.

Desert lilies lined the trail Calcite Mine Palm Wash Loop at Anza-Borrego State Park.

So beautiful despite very little water being available to support them.

Desert lilies lined the trail Calcite Mine Palm Wash Loop at Anza-Borrego State Park.

Just below the ridge were the sediment walls of the Palm Wash.

Towering walls of the Palm Wash on the Calcite Mine Loop at Anza-Borrego State Park
Towering walls of the Palm Wash on the Calcite Mine Loop at Anza-Borrego State Park

Some of these hills resembled the landscape in Death Valley with the mineral colored hillsides.

Colorful hillsides on the Calcite Mine Loop at Anza-Borrego State Park

Narrow canyons display the incredible power of flowing water which eroded deep gashes through the sandstone.

Narrow canyons along the Palm Wash on the Calcite Mine Loop at Anza-Borrego State Park

We finally reached a spot with views of the Salton Sea.

Views of the Salton Sea from the Calcite Mine Loop at Anza-Borrego State Park

Numerous examples of wind and rain erosion in the rock face.

Wind and rain erosion on surface of sediment rocks on the Calcite Mine Loop at Anza-Borrego State Park

After about 2 miles of hiking we reached a sign that marked the mine entrance.

Sign for the Calcite Mine Area in Anza-Borrego State Park

Calcite is a common mineral, a form of calcium carbonate, similar in basic chemical composition to chalk and gypsum and is a basic material for cement. There are at least 800 different forms of crystalline calcite. These differ in color and in light transmission from completely opaque to translucent. The calcite crystals mined here were colorless and transparent.

Hiking in the Calcite Mine area of Anza-Borrego State Park

Calcite was an essential component of the Norden bombsight. The Norden bombsight was one of America’s most closely guarded secrets during World War II. It was the state of the art in the 1940s and used to calculate the trajectory of a bomb being dropped from high altitudes. It enabled American airplanes to hit ground targets in daylight raids from an altitude of six miles.

Hiking in the Calcite Mine area of Anza-Borrego State Park

Calcite was mined by digging trenches along calcite-containing seams. The trenches can be recognized by their unnatural regularity. Small calcite crystals were everywhere glistening in the sun light.

Small calcite crystals found in the Calcite Mine area of Anza-Borrego State Park

You could see mine trenches slashing through the terrain.

Calcite Mine trenches in the Calcite Mine area of Anza-Borrego State Park

Our lunch-time location was a hilltop a short walk away.

Red sediment hilltop along the Calcite Mine Loop at Anza-Borrego State Park

We had perfect lunch-time views.

Eroded hills and mountains along the Calcite Mine Loop at Anza-Borrego State Park
Eroded hills and mountains along the Calcite Mine Loop at Anza-Borrego State Park

On our way back, we explored one of the many side canyons.

Hiking Calcite Mine Palm Wash Loop at Anza-Borrego State Park
Narrow canyons along the Palm Wash on the Calcite Mine Loop at Anza-Borrego State Park

The canyon narrowed the further we traveled.

Hiking side slot canyons wash along the Calcite Mine Loop at Anza-Borrego State Park

and just like that, we reached a 20+ foot dry fall that prevented us from going further.

Hiking side slot canyons wash along the Calcite Mine Loop at Anza-Borrego State Park

We weren't ready to give up so we headed back to the main canyon and followed a different wash.

Narrow canyons along the Palm Wash on the Calcite Mine Loop at Anza-Borrego State Park

This trail was more enjoyable since it quickly turned into a slot canyon, but

Hiking side slot canyons wash along the Calcite Mine Loop at Anza-Borrego State Park

it came to an abrupt ending with another dry fall that was impossible to maneuver around or down.

Smooth walls eroded by water in slot canyons along the Calcite Mine Loop at Anza-Borrego State Park

We returned to the main canyon and instead of following the mine road we headed into the Palm Canyon wash.

Narrow canyons along the Palm Wash on the Calcite Mine Loop at Anza-Borrego State Park

The wash narrowed and they became smooth as glass.

Smooth walls eroded by water in slot canyons along the Calcite Mine Loop at Anza-Borrego State Park

Water from recent rains or percolating groundwater made for some slow going.

Hiking through water in a slot canyon in Anza Borrego State Park

The wash widened again and we were back to walking through soft sand and boulder fields.

Towering walls of the Palm Wash on the Calcite Mine Loop at Anza-Borrego State Park
Hiking Calcite Mine Palm Wash Loop at Anza-Borrego State Park

Unfortunately, we missed the spot where the wash turned back to the trail head. It was a nice day to extend the hike but we needed to find a location where the canyon walls gave way to hills that we could scale to get back on the trail.

Towering walls of the Palm Wash on the Calcite Mine Loop at Anza-Borrego State Park

After scrambling up a few hills, we found the trail back to our starting point ...only a few extra miles.

Hiking Calcite Mine Palm Wash Loop at Anza-Borrego State Park

the planned trail our actual path


A few extra miles, but well worth it.



21 views0 comments