# Relationship history for MSHA mine 0504013

Current hierarchy: **Glenn E  Southwick → Masonville Stone Company → MASONVILLE QUARRY**

- 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:** Masonville Stone Company → MASONVILLE QUARRY; 1985-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Glenn  Southwick et al → MASONVILLE QUARRY; 1985-03-01 to 2020-02-11; source msha-controller-operator-history
- **controller_controls_operator:** Glenn  Southwick et al → Masonville Stone Company; 1985-03-01 to 2020-02-11; source msha-controller-operator-history
- **controller_controls_operator:** Dave  Bacon et al → Masonville Stone Company; 1985-03-01 to 2020-02-11; source msha-controller-operator-history
- **controller_controls_mine:** Glenn E  Southwick → MASONVILLE QUARRY; 2020-02-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Glenn E  Southwick → Masonville Stone Company; 2020-02-12 to current/open; source msha-controller-operator-history