Looks like a short segment of old tracks going away. Appears the track was part of a spur to Arcata and whatever customers were there. Bye bye, railroad.
"County Supes Vote to Spend $600K in State Funds to Buy Two Parcels Needed to Complete the Bay Trail"
"Uri Driscoll called in to voice concern about maintaining the option for future rail use along the North Coast Railroad Authority right-of-way. “I’d like to hear a commitment to replacing the rail,” he said. The long debt-saddled NCRA was all-but-obliterated two years back with passage of Sen. Mike McGuire’s “Great Redwood Trail Act,” which aims to create a 300-mile path between San Francisco and Humboldt Bay."
https://lostcoastoutpost.com/2020/oct/6/today-supes-october-6-2020/
"Construction of the last unfinished stretch of the Humboldt Bay Trail is currently scheduled to begin in the summer or fall of 2021."
"Aerial view of the parcels as they looked last May. One of the billboards pictures here has since toppled over, and its remnants were removed permanently."