Erosion Line Journal
January 19, 2025
Today, the lower park of Maidu trail was finally dry enough Jose and Dakota tackle. Attempts a couple of weeks ago, following the rainiy November and December, resulted in aborted motifs as the bedrock was too crumbly to continue.
We start each motif by first making the ‘tip’ of the triangle – the hole that touches the existing edge of soil. This is the most important feature of each motif as it will provide the reference point from which to measure future erosion. If the bedrock isn’t stable for this hole, we move to a different location. But today, most every spot we tried worked. We ended up with many beautiful new motifs that connected two previously completed sections of trail.
January 15, 2025
Julia, Aidan, and I tried a section of the Maidu trail that was previously to fragile to work. The dry weather worked its magic and we were able to make clean, round holes for the motifs. Aidan also worked on boulder motifs further up the trail.
January 12, 2025
Another beautiful day in the Park, we got a lot done. Vanessa, Brandon, Jess, and Chris continued on patch of exposed bedrock that was dry and sturdy enough to work. There’s a gap in the Erosion Line where we skipped sections that were unworkable after the rains. Two rainless week have allowed this part of the trail workable.
January 11, 2025
Aidan and I focused on portions of the Maidu Trail that are composed of soil, with no exposed bedrock. The soil is easily displaced by normal trail use and erosion was apparent. Making the motifs on boulders will help track the progression of erosion.
January 5, 2025
Lisa, Eliana, and Tom worked a layer of exposed bedrock that, though wetted by rain a day ago, was firmer than other bedrock on Maidu trail. Much of the bedrock in Upper Bidwell Park is composed of volcanic material deposited in layers over millions of years. Generally, these layers feel and look like ‘petrified’ mud. But there is a subtle variety of textures and materials that affect our work. Some layers are composed of fairly uniform fine particles, like sandstone. Others have large, chunky aggregates in mud-like matrix. Some are etched with hairline cracks, like clay that has dried too fast. Each trail section requires assessment of the characteristics of the bedrock and whether rain penetration has rendered it temporarily too unstable. We adapt carving techniques and what trail section we choose to work to reflect conditions.
January 4, 2015
Aidan and Humberto, having a grand time demonstrating creative ways to make motifs in boulders.
Some portions of the Monkey Face and Maidu trails feature bare soil with no exposed bedrock. But, like the bedrock, many of the boulders that sit in the middle of trails have been completeley or partially exposed by trail erosion. By making motifs at the soil line at base of these boulders, we can track future erosion.
December 21, 2024
Aidan: I went on a hike when we had a break in the weather this past Tuesday. Took the liberty of measuring the erosion from the past three weeks-
Eve: Wow, thank you for doing that and sending these great images! I went up the Maidu trail and noticed erosion at several of the motifs. Also several were completely covered with deposits from erosion uphill. Its shocking how quickly it happens!
Aidan: Right? Did not expect to see results that fast.
December 19, 2024
Spent a lovely, foggy, drippy morning leading North State Public Radio’s Ava Norgrove on a tour of the Erosion Line. She had previously interviewed me in the NSPR studio but wanted to come out in person. She helped make a motif and produced a wonderful segment that aired on the radio and is posted on the NSPR website. Thank you for lending your talents for in-depth reporting and helping to get the word out, Ava! We are fortunate to have high quality local journalism in our region!
December 11, 2024
So moving to learn that today’s volunteer, Adia, chose to work on the Erosion Line today in memory of her father, who passed away two years ago. Thank you for honoring this project with your respectful presence, Adia.
December 8, 2024
Today’s volunteer, Kyle, worked with me on exposed bedrock on Monkey Face. He developed a more streamlined chiseling technique by rolling the chisel back and forth between thumb and index finger rather than continuously in one direction. Seems to require less dexterity and cause less tearing in soft bedrock. Thank you Kyle!
December 7, 2024
Back to working on Monkey Face with Aidan. Motifs in November are showing that, following a recent big rain event, several inches of soil has been eroded away in some areas. The point of the triangular motif, next to my thumb, used to touch the edge of soil. The current edge of soil touches my pinky in this image.
November 30, 2024
Volunteers Paul and Katy continued work on Maidu trail as Monkey Face bedrock is still quite fragile. As we make motifs, we discuss Paul and Katy’s ideas to promote a community culture of stewardship for Bidwell Park by coordinating with the many service groups already involved in the park. They are working to organize a 120-year Park anniversary event to galvanize volunteerism in Bidwell Park.
November 27, 2024
Today, the bedrock on Monkey Face trail is rain soaked and too fragile to work. Volunteers Calvin and Aidan are working on Maidu trail. The bedrock is not too soft here, so workable. We work carefully to prevent blow outs, starting each hole with a narrow 1/4″ chisel then finishing with a 3/8″ chisel. Delicate tapping and turning – drilling, not pounding.
November 23, 2024
Aidan is back! He’s a recent biology major volunteering on environmental projects while seeking work in his field. Thrilled to have his continued help on Monkey Face trail! The bedrock, softened by rain, was too fragile to work. We made motifs on the vertical faces of boulders that are imbedded in soil and on the faces of stone steps. These large stones are much harder that the bedrock. The angle can be a bit tricky but we found it quite gratifying to make motifs in them!
November 16, 2024
Inaugural EL event with community volunteers! Here we are: Aidan, Sally, me, Stephanie, and Fernanda on Monkey Face trail, ready to get started. We worked in teams of two, one making holes while the other made sure that the chisel is held perpendicular to the slope of the bedrock to prevent shearing. Got a lot done!
November 15, 2024
Action New reporter Diego Moctezuma came out to interview me and film the future site of the Erosion Line on Maidu trail in Upper Bidwell Park, Chico CA. He attended the BPPC meeting where the project was approved and kindly followed up. Thank you for covering the Erosion Line, Diego! I hope to see you out on the trail soon! You can read his informative story and watch the segment here!
September 29, 2024
Test run #3! Dear friends Laura, Mari, Carla, Mary, Suzanne, and Jeanette arrived for the final trial run. We refined our techniques on horizontal volcanic bedrock which is somewhat friable and workable. Also tried some holes on upright faces on boulders that protrude from portions of the trail still covered in soil. Much harder but doable.
September 23, 2024
Test run #2, with volunteer and dear friend Julia!
September 16, 2024
Earthen Iron’s Dave Richer kindly sharpened the star chisels. Ready for action!
September 15, 2024
Now that the project has been approved by the Bidwell Park and Playground Commission, it’s time to see if the theory works: can small holes be carved into the erosion-exposed bedrock on Monkey Face? Using a two-pound mallet, I carefully tap-turn-tap a star chisel provided by Chico sculptor Matt Auvinen. This traditional sculpting tool is used to hand-drill holes in masonry and stone. The hole takes shape. Soon, I’ve made a 3-dot motif! It works!
September 6
Chico sculptor Matt Auvenin kindly advises me on the best way to make holes in stone. He pulls out some antique star chisels, traditional hand tools that look somewhat like phillips head screwdrivers but with sharpened edges. When slowly turned while being tapped by a mallet, they drill a neat hole into the surface that is to be perforated. I leave this informative meeting with four star chisels of varying size and a 3 pound mallet that Matt has donated. Thank you, Matt!
August 26, 2024
Following a slide presentation and a thoughtful question and answer period, the Bidwell Park and Playground Commission voted unanimously to approve the Erosion Line project!