Cleone, CA Coastal Erosion Rate
What USGS measures 11.3 miles north of Cleone, CA
0.42 feet a year: that is the measured retreat rate USGS's transects show for the coast 11.3 miles north of Cleone, CA, averaged across the full historical record surveyed here. At that rate, the shoreline has lost roughly 4.2 feet over the last decade.
The grain of this number
Nothing here is parcel-level. USGS's raw transects run every few hundred feet along the shore; this page averages the ones nearest Cleone, CA into one ~3.5-mile reading rather than picking a single arbitrary line to represent the area. Centered near 39.65°N, 123.79°W. The survey behind it runs to 1852-2016, in USGS's California assessment, using the LRR method. Shoreline surveys aren't repeated every year, so this is the most recent long-term measurement USGS has published for this coast, not a live reading.
25 years at this rate
If 0.42 ft/yr holds for the next 25 years, the coast 11.3 miles north of Cleone, CA would retreat roughly 11 more feet, a projection, not a certainty: erosion rates shift with storms, sediment supply and any armoring built in the meantime.
What backs this reading up
79 transects feed this segment's number; 89% of them individually measured retreat. The published margin on this reading runs ±0.32 ft/yr. Among the 1211 US coastal segments with a measurable trend, this one ranks 341 for erosion, 1 being the fastest-retreating coast in the dataset. Source: USGS National Shoreline Change data release (ScienceBase, DOI 10.5066/P94J0K7Z), Kratzmann 2024 / Data Report 1187. Rank 41 nationally for erosion belongs to Triumph, LA, 2067 miles from this stretch, measured at 6.26 ft/yr, many times over this stretch's own rate. Cleone, CA, 2.6 miles off, is the adjacent measured stretch, itself no significant trend.
Cleone, CA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.