# Relationship history for MSHA mine 2301337

Current hierarchy: **David K  Willard → Willard Quarries Inc → Bagnell Dam 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:** Ozark Sand Company Inc → Bagnell Dam Quarry; 1950-01-01 to 1982-10-25; source msha-controller-operator-history
- **controller_controls_mine:** Everett Holding Co  et al → Bagnell Dam Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Everett Holding Co  et al → Ozark Sand Company Inc; 1950-01-01 to 1982-10-25; source msha-controller-operator-history
- **controller_controls_operator:** Clarkson Construction Co et al → Ozark Sand Company Inc; 1950-01-01 to 1982-10-25; source msha-controller-operator-history
- **controller_controls_mine:** David K  Willard et al → Bagnell Dam Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Willard Quarries Inc → Bagnell Dam Quarry; 1982-10-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David K  Willard et al → Willard Quarries Inc; 1982-10-26 to current/open; source msha-controller-operator-history