# Relationship history for MSHA mine 3608821

Current hierarchy: **Sandra I  Wood; David P  Wood → Oakridge Bluestone → Oakridge Bluestone IV**

- 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:** William O  Wood → Oakridge Bluestone IV; 1999-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lyons Quarries → Oakridge Bluestone IV; 1999-10-01 to 2003-07-13; source msha-controller-operator-history
- **controller_controls_mine:** Lawrence  Lyons → Oakridge Bluestone IV; 1999-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lawrence  Lyons → Lyons Quarries; 1999-10-01 to 2003-07-13; source msha-controller-operator-history
- **operator_operates_mine:** William Wood → Oakridge Bluestone IV; 2003-07-14 to 2005-08-17; source msha-controller-operator-history
- **controller_controls_operator:** William O  Wood → William Wood; 2003-07-14 to 2005-08-17; source msha-controller-operator-history
- **controller_controls_mine:** David P  Wood et al → Oakridge Bluestone IV; 2005-06-25 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Oakridge Bluestone → Oakridge Bluestone IV; 2005-08-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David P  Wood et al → Oakridge Bluestone; 2005-08-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sandra I  Wood et al → Oakridge Bluestone; 2005-08-18 to current/open; source msha-controller-operator-history