California Boring Logs & Geotechnical Data
44,538 public boring logs in California; 5,085 with digitized SPT, soil or CPT data; 39,453 scanned log PDFs. Sources include Caltrans, LA County Public Works (GMED), USGS CPT program, plus public reports found by web crawl. Free to search on the map, download or query by API.
Where the data comes from
- Caltrans26,250
- LA County Public Works (GMED)9,483
- Public reports collected by web crawl7,800
- USGS CPT program1,005
Web-crawled reports in California were published on, among others: dehpra.acgov.org, sandiego.gov, sandiegocounty.gov, lus.sbcounty.gov, planning.lacity.gov, waterboards.ca.gov.
Counties with the most boring logs
| County | Boring logs | |
|---|---|---|
| Los Angeles | 15,865 | view on map |
| San Diego | 3,293 | view on map |
| Orange | 3,253 | view on map |
| San Bernardino | 2,168 | view on map |
| Alameda | 1,707 | view on map |
| Riverside | 1,507 | view on map |
| Santa Clara | 1,260 | view on map |
| San Mateo | 819 | view on map |
| Ventura | 817 | view on map |
| Contra Costa | 732 | view on map |
| Kern | 698 | view on map |
| Sacramento | 673 | view on map |
What's in a boring log from California
The 5,085 digitized borings carry the data engineers actually use: SPT blow counts (N-values) by depth, soil and rock descriptions, groundwater observations and, where the source ran cone penetration tests, CPT tip resistance and sleeve friction. A further 39,453 logs are scanned PDF reports — the original agency drawings — which you can open and download from the map. Holes are typically about 25 ft (8 m) deep; one in twenty goes past 82 ft (25 m). Not sure what a boring log looks like? See annotated example boring logs.
How to get this data
- Map — pan to a site, click a boring, and view the log, the original PDF, or an ML soil-profile prediction. No account needed.
- Downloads — every boring exports as PDF, DIGGS XML or AGS4; draw a polygon on the map for a multi-boring export or a site report.
- API — query borings by coordinates or bounding box, pull SPT/CPT/lab records, and generate site reports programmatically.
- Contribute — have California boring logs that are not here yet? We take PDFs, DIGGS, AGS and spreadsheets.
This data was collected from public agencies and is republished as-is. It is a planning tool, not a substitute for a site investigation; see the terms and disclaimer. Counts refreshed 23 September 2026.
Other places
Florida (169,311)Washington (151,928)North Carolina (99,630)Ohio (78,319)Oregon (61,119)New Jersey (49,418) all regions →