# Relationship history for MSHA mine 2402092

Current hierarchy: **Richland County-Mt → Richland County Public Works → RICHLAND PORTABLE**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Richland County-Mt → RICHLAND PORTABLE; 1993-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Richland County Public Works → RICHLAND PORTABLE; 1996-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richland County-Mt → Richland County Public Works; 1996-05-01 to current/open; source msha-controller-operator-history