# Relationship history for MSHA mine 3304458

Current hierarchy: **W Thomas  Mackall → East Fairfield Coal Co. - Limestone Division → Petersburg 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

- **controller_controls_mine:** W Thomas  Mackall et al → Petersburg Mine; 1996-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** East Fairfield Coal Co. - Limestone Division → Petersburg Mine; 2000-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** W Thomas  Mackall et al → East Fairfield Coal Co. - Limestone Division; 2000-05-01 to current/open; source msha-controller-operator-history