# Relationship history for MSHA mine 1201009

Current hierarchy: **Vulcan Materials Company → VULCAN CONSTRUCTION MATERIALS, LP → HANNA SAND & GRAVEL**

- 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) → HANNA SAND & GRAVEL; 1950-01-01 to 2007-11-15; source msha-controller-operator-history
- **operator_operates_mine:** Medusa Aggregates Company → HANNA SAND & GRAVEL; 1950-01-01 to 1978-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Medusa Corp → HANNA SAND & GRAVEL; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Medusa Corp → Medusa Aggregates Company; 1950-01-01 to 1978-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Crane Company → HANNA SAND & GRAVEL; 1978-12-13 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Medusa Aggregates Company → HANNA SAND & GRAVEL; 1979-01-01 to 1982-12-19; source msha-controller-operator-history
- **controller_controls_operator:** Crane Company → Medusa Aggregates Company; 1979-01-01 to 1982-12-19; source msha-controller-operator-history
- **operator_operates_mine:** Vulcan Materials Company → HANNA SAND & GRAVEL; 1982-12-20 to 1987-09-24; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → Vulcan Materials Company; 1982-12-20 to 1987-09-24; source msha-controller-operator-history
- **operator_operates_mine:** Critser Companies Inc → HANNA SAND & GRAVEL; 1987-09-25 to 2005-08-07; source msha-controller-operator-history
- **controller_controls_mine:** William J  Critser et al → HANNA SAND & GRAVEL; 1987-09-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William J  Critser et al → Critser Companies Inc; 1987-09-25 to 2005-08-07; source msha-controller-operator-history
- **controller_controls_operator:** Jean A  Critser et al → Critser Companies Inc; 1987-09-25 to 2005-08-07; source msha-controller-operator-history
- **operator_operates_mine:** VULCAN CONSTRUCTION MATERIALS, LP → HANNA SAND & GRAVEL; 2005-08-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → VULCAN CONSTRUCTION MATERIALS, LP; 2005-08-08 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Vulcan Materials Company → HANNA SAND & GRAVEL; 2007-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → Vulcan Materials Company; 2007-11-16 to 1987-09-24; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → VULCAN CONSTRUCTION MATERIALS, LP; 2007-11-16 to current/open; source msha-controller-operator-history