# Relationship history for MSHA mine 1200769

Current hierarchy: **RR Holdco, Inc. → Phend & Brown, Inc. → Leesburg 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

- **operator_operates_mine:** Medusa Aggregates Company → Leesburg Sand & Gravel; 1950-01-01 to 1978-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Medusa Corp → Leesburg 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 → Leesburg Sand & Gravel; 1978-12-13 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Medusa Aggregates Company → Leesburg Sand & Gravel; 1979-01-01 to 1979-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Crane Company → Medusa Aggregates Company; 1979-01-01 to 1979-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Phend & Brown, Inc. → Leesburg Sand & Gravel; 1979-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Douglas V Brown et al → Leesburg Sand & Gravel; 1979-12-01 to 2021-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Douglas V Brown et al → Phend & Brown, Inc.; 1979-12-01 to 2021-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Daniel F Brown et al → Phend & Brown, Inc.; 1979-12-01 to 2021-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Rieth-Riley Construction Company Inc → Leesburg Sand & Gravel; 2022-01-01 to 2025-01-30; source msha-controller-operator-history
- **controller_controls_operator:** Rieth-Riley Construction Company Inc → Phend & Brown, Inc.; 2022-01-01 to 2025-01-30; source msha-controller-operator-history
- **controller_controls_mine:** RR Holdco, Inc. → Leesburg Sand & Gravel; 2025-01-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** RR Holdco, Inc. → Phend & Brown, Inc.; 2025-01-31 to current/open; source msha-controller-operator-history