Calcite Mine Trail

4.2/5 (8 reviews)
Salton City, California (San Diego County)
Last Updated: 09/26/2022
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Trail Information

Highlights

The Calcite Mine is a historic landmark and off-road trail in the Truckhaven Hills in the desert of Anza Borrego State Park located in the southeast corner of California. Because of the uniqueness of the mine, many people stop here when doing overland trips through the deserts of Southern California to take in the beauty of the area and the history. Getting to the mine is a moderate 4x4 trail with several obstacles that require a person to pick the appropriate line for their vehicle. This is a very short off-road run, perfect for a night run or a quick day trip if either dispersed camping or driving through the area. There are also several slot canyons in the area surrounding the Calcite Mine that make for a great hike.

Trail Difficulty and Assessment

Trail Navigation

***Unconfirmed but likely - the trail has been graded and is now easy. We lowered the rating till we can confirm this so there is still a small chance of an obstacle on the trail*** Several obstacles are on this trail, including some rock crawling, off-camber sections, hill climbs, and many small washouts along the cliffside of the trail. Along the route are several slot canyons, ledges, hill climbs, sand, and exploring. The narrow shelf road trail has many washouts, requiring close attention to the trail. Please pay attention to the trail at all times to avoid the possibility of driving over the edge.
This can be a popular trail at times throughout the year, please watch out for traffic.

Trail Reviews

4.2/5 (8 reviews)
Status: Open
Rated 4/5
Visited: 02/04/2021

I can conform the road has been graded. Even 2WD with moderate clearance would be perfectly fine for this trail. Calcite is everywhere up there. Nice views and hiking options.
Trail Review: Calcite Mine Trail - Paul Crawford
Trail Review: Calcite Mine Trail - Paul Crawford
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Status: Open
Rated 5/5
Visited: 01/31/2021

I love this little route. Mostly because of the history of the World War II effort and this mine. Anza Borrego park and World War II So how does World War II war effort factor into Anza Borrego Desert? Literally within 5 miles of where our RV is located we found an interesting 4 x 4 route. The route is called the calcite mine trail. Earlier investigation didn’t intrigue me so it wasn’t on my list. As I started to research calcite and what calcite was used for that’s why and it peaked my interest. This calcite mine was developed during World War II, general Patton‘s troops built the original road that leads north from here to the former calcite mine. This was the top producing calcite mine in North America. It was important to the war effort, because calcite is a form of calcium carbonate. When you strike calcite Kristal, it will break into pieces that have exact angles and clear flat sides that provide double refraction properties. The Polaroid company processed these into optical ring sites for the military. Gunners and torpedo bomber’s depended on calcite Ring sites for the most accurate aim available. Today you can wander around the area and you’ll find honeycombs of the calcite veins and lots of empty pockets where the minors have been. Initial thought was they look like slot canyons, but they are actually where the minors were following the veins of calcite. I should also add that the road has been repaired so there are no obstacles on this road. Four-wheel-drive is recommended but I do think you could do this trip in a 2 Wheel Drive.
Ben
1500
Status: Open
Visited: 11/27/2020

It has been flattened to a dirt road. I saw a Subaru driving it. I was disappointed. The area is still very interesting. I saw the slot canyon, hiked a trail to a lookout point, and there was more hiking I could have done.
Status: Open
Rated 1/5
Visited: 10/13/2020

Just visited this trail over the weekend. It is now a flat graded road all the way to the mine. I could drive my moms Buick on this road. It is no longer at 4 out of 4 trail rated. I will say there is an obstacle at the mine parking area on the left that is fun. Otherwise not much of a technical trail anymore. Rob
Status: Open
Rated 5/5
Visited: 01/04/2020

Ran this for first time with group. The guys I was with were saying that it was unfortunately graded. Maybe it was because I dont remember the v notch and large hole?? The scariest part was close to the top were the trail narrows with a washout off camber. All our trucks made it including the widest wheelbase hummer h3. Coming down in my 5th gen 4runner, my back slipped sideways on that section. Yikes! The mine was no what I expected, but very cool. Interesting history. The calcite was used in b17 bombers for bomb sights during ww2. It was only 2 places (the other in montana) that was supplied by Polaroid once it was determined that domestic sources were needed. A few years later, synthetic calcite with almost identical optical properties was invented and used. Calcite veins are mostly exposed and 2-20 something guys chiselled and hammered the rock on both sides of these veins to extract the optical grade calcite with least amount of damage as possible. Good specimens needed to be at least 0.5x2.0 inches in size. I've read that the men did this on volunteer basis in summer heat!! I dont know if they did this for war effort?
Trail Review: Calcite Mine Trail - Tj Sleboda
Trail Review: Calcite Mine Trail - Tj Sleboda

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