# Relationship history for MSHA mine 3800642

Current hierarchy: **Cogdill Ronald F & Paul I Lawson → Cogdill & Lawson Sand → Lanford Mine**

- 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

- **operator_operates_mine:** Cogdill & Lawson Sand → Lanford Mine; 1990-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cogdill Ronald F & Paul I Lawson → Lanford Mine; 1990-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cogdill Ronald F & Paul I Lawson → Cogdill & Lawson Sand; 1990-01-01 to current/open; source msha-controller-operator-history