Colorado 2020: Treading

This post continues the retelling of my AmeriCorps service term in Colorado in 2020. The rest of this serious can be found here.

July 28, 2020 was our second day working on the Fern-Mesa reroute project. This was the day when we learned how to perform a task called “treading.”

On the 28th, we returned to the spot where we had worked on the previous day. Once again, we drove through the glistening town of Boulder, through a cattle gate that was next to someone’s (expensive) house, and then over a well-polished hiking trail until we could drive no further.

We then disembarked from our van, grabbed our tools, and hiked for a few minutes to our worksite.

Once there, we began by finishing up some restoration work from the day before. At some point during our workday, we had to move rocks that were too heavy for us to lift. That’s when Jo and Kait – our main contacts with the City of Boulder – taught us how to use rock bars.

A rock bar is a long, thin metal bar that’s tapered at one end. As Kait and Jo showed us, to move a rock with a rock bar, you wedge the tapered end of the bar under the rock. You then apply pressure to your end of the bar and ‘row’ to move the rock in the desired direction.

Of course, that’s the most basic description for how to use a rock bar. It can become quite complex, especially when you start adding fulcrums at various points of the bar to turn it into a lever, if two or more people are working together, or if there are people below you that you’d rather not drop a boulder on.

I had fun playing with rocks and levers for a while, and making zero progress, but after lunch Kait and Jo moved me to a different task – probably because of the zero progress part. This time they decided to punish me by teaching me how to tread.

Treading was invented by the Devil. It involves putting the finishing touches on the part of a trail that people walk on, which is called the tread. Treading can be painfully exact – depending on the requirements of whomever you’re working for – and everything I’ve said about the City of Boulder should indicate that they were very meticulous.

The city required their trails to have a 5º outslope whenever possible. This means that their trails had to slope towards the outside edge at an angle of five degrees.

If you’ve never had to measure a 5º angle before, it’s barely perceptible to the human eye. To make sure we weren’t destroying the world by building a trail with an improper angle, we had boards that had been cut to exactly 5º. These boards had levels on them, so that when we placed a board on a piece of tread and the bubble settled in the middle of the level, we knew that our tread was angled correctly.

We called these boards trail gauges.

Treading went as follows. We’d take a pick-mattock (more commonly just called a pick), shave off a little bit of the tread, and then measure it with a trail gauge to see how far off 5º we were.

The answer was typically a lot, so then we’d remove more of the tread before re-measuring.

At this point our trail gauges would usually tell us that we were still a long way off from a 5º outslope. Naturally, then, we’d chip away at the tread a little more and check our work. Then we almost invariably found that we’d gone past 5º.

I found the treading process to be maddeningly slow at first, but eventually I got the hang of it. Of course, this happened right as it was time to leave. Once it approached 5:00 in the evening, we gathered our tools, hiked back to our van, and drove home.