What a Mine Safety Inspection Record Can Tell You
Every inspection entry on MSHAScan is a small piece of MSHA public data, but it can tell you far more than whether an inspector visited a mine. A single record shows when the inspection happened, how much time MSHA spent on site, how many inspectors were involved, which operator controlled the mine at the time, and how to connect that event to violations issued during the same inspection. For journalists, researchers, and mine workers, that context makes inspection data much more useful than a simple count.
What appears in an MSHA inspection record
MSHAScan surfaces the fields that are most useful for reading inspection history. The underlying MSHA inspections dataset includes additional administrative columns, but the core fields most readers will encounter are the ones below.
Identifiers and dates
- Event number: MSHA's unique identifier for the inspection. This is the key that lets you connect one inspection to any related citations or orders in MSHA's violations data.
- Mine ID: The seven-digit identifier for the mine. This ties the inspection to the mine's profile, operator history, commodity, location, and other records.
- Inspection begin date and end date: These tell you when the event started and ended. A same-day inspection can look very different from one that spans several days.
Who the record is attached to
- Operator name: The company running the mine when the inspection was logged.
- Controller name: The controlling entity, which can matter when ownership is layered through parent companies or affiliates.
These fields help when a mine changes hands. A violation trend or inspection pattern may look different once you separate records by operator or controller instead of treating the mine as one uninterrupted story.
What MSHA was inspecting
- Activity code: A code used by MSHA to identify the inspection activity or event type.
- Active sections: A field that can indicate which working sections or areas of the mine were involved.
How much inspection work was involved
- Total hours: The total inspection hours recorded for the event.
- On-site hours: When available, the portion of inspection time spent at the mine rather than on related administrative work.
- Number of inspectors: How many inspectors participated in the event.
What those fields can reveal about a mine
Operational scale and complexity
Longer inspections, multiple inspectors, and repeated events during a year often point to a larger or more complex operation. A small surface site and a large underground mine should not be expected to generate the same inspection footprint.
Ownership and accountability over time
Operator and controller fields help distinguish a mine's physical location from the company responsible for it. That matters when reporters are tracing changes after a sale, researchers are building time series, or workers are comparing management eras.
A bridge to the rest of the safety record
The event number is one of the most useful fields in the file. MSHA's violations dataset is tied to inspections through that event number, which means an inspection entry can be the starting point for deeper reporting.
How to interpret inspection frequency
Start with MSHA's inspection requirements
Each underground mine is generally inspected at least four times a year and each surface mine at least twice a year. Some mines are inspected more often because of gas hazards, complaints, special conditions, or follow-up work.
What a high inspection count may mean
A high count can reflect routine statutory coverage at an active underground mine. It can also reflect complaint-driven activity, follow-up inspections, or a long-running operational issue. The count by itself does not tell you which explanation applies.
What a low inspection count may mean
A low count may simply reflect a surface mine, a mine that was inactive for part of the year, or a mine with limited inspectable activity.
How to interpret hours and inspector counts
Hours measure scope, not guilt
More hours can mean a mine is large, remote, technically complex, or spread across multiple areas. A 40-hour inspection is not automatically worse than a 10-hour inspection.
Inspector counts show staffing, not just seriousness
Multiple inspectors on one event can signal a broader inspection team, a training component, or a mine large enough to require several people.
How different readers can use the record
For journalists and researchers
Use inspection records to avoid thin stories built on violation counts alone. Check whether a spike in citations came from one intensive inspection or many separate visits. Use the event number to join inspection data to violation data before drawing conclusions.
For mine workers and community members
Inspection history can show whether MSHA has been present recently, whether visits are short or extensive, and whether a mine's ownership has changed.
Read inspection records in context
An MSHA inspection record is best read as a structured summary of agency oversight, not as a scorecard by itself. On MSHAScan, those records come from MSHA's official open data, which means they are most useful when read alongside mine profiles, violations, and accidents.