# Relationship history for MSHA mine 4400051

Current hierarchy: **Doug  Dalton → Holston River Quarry Inc → Holston River Quarry Incorporated**

- 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:** State Contracting & Materials Division → Holston River Quarry Incorporated; 1950-01-01 to 1979-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Medusa Corp → Holston River Quarry Incorporated; 1950-01-01 to 1979-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Medusa Corp → State Contracting & Materials Division; 1950-01-01 to 1979-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Crane Company → Holston River Quarry Incorporated; 1978-12-13 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Medusa Aggregates Company → Holston River Quarry Incorporated; 1979-02-01 to 1980-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Crane Company → Medusa Aggregates Company; 1979-02-01 to 1980-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Holston River Quarry Inc → Holston River Quarry Incorporated; 1980-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Doug  Dalton → Holston River Quarry Incorporated; 1980-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Doug  Dalton → Holston River Quarry Inc; 1980-10-01 to current/open; source msha-controller-operator-history