# Relationship history for MSHA mine 1100291

Current hierarchy: **Vulcan Materials Company → Vulcan Materials Company → WESTON 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → WESTON QUARRY; 1950-01-01 to 2007-11-15; source msha-controller-operator-history
- **operator_operates_mine:** Pontiac Stone Company → WESTON QUARRY; 1950-01-01 to 1981-12-14; source msha-controller-operator-history
- **controller_controls_mine:** Albert  Lamb → WESTON QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Albert  Lamb → Pontiac Stone Company; 1950-01-01 to 1981-12-14; source msha-controller-operator-history
- **operator_operates_mine:** Vulcan Materials Company → WESTON QUARRY; 1981-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Vulcan Materials Company; 1981-12-15 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Vulcan Materials Company → WESTON QUARRY; 2007-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Vulcan Materials Company; 2007-11-16 to current/open; source msha-controller-operator-history