Data by place › United States › Iowa

Iowa Boring Logs & Geotechnical Data

1,530 public boring logs in Iowa; 1,062 with digitized SPT, soil or CPT data; 468 scanned log PDFs. Sources include Iowa DOT, University of Nebraska–Lincoln, Wisconsin DOT (WisDOT), plus public reports found by web crawl. Free to search on the map, download or query by API.

1,530
Boring logs
1,062
Digitized
1,114
With PDF
1962–2025
Drilled
25 ft
Typical depth (8 m)
Where the 1,530 logs are — darker cells hold more borings. Click to open the map.
Open the Iowa map →

Where the data comes from

Web-crawled reports in Iowa were published on, among others: navigationdistrict.org, programs.iowadnr.gov, bidopportunities.iowa.gov, iowaagriculture.gov, pubs.usgs.gov, storycountyiowa.gov.

Counties with the most boring logs

CountyBoring logs
Johnson151view on map
Polk131view on map
Linn74view on map
Calhoun72view on map
Kossuth71view on map
Pottawattamie70view on map
Plymouth60view on map
Fremont59view on map
Dubuque51view on map
Woodbury46view on map
Clinton40view on map
Dallas31view on map

What's in a boring log from Iowa

The 1,062 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 468 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 373 ft (114 m). Not sure what a boring log looks like? See annotated example boring logs.

How to get this data

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 2 September 2026.

Other places

Florida (168,718)Washington (151,445)North Carolina (99,509)Ohio (78,203)Oregon (61,067)New Jersey (49,412) all regions →