# Relationship history for MSHA mine 4002772

Current hierarchy: **Morrison Knudsen Corp (Old) → Blue Ridge Mining Company Inc → Chesney Surface Mine #3**

- 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

- **controller_controls_mine:** Preston Carroll Enterprises Inc → Chesney Surface Mine #3; 1950-01-01 to 1984-09-03; source msha-controller-operator-history
- **operator_operates_mine:** Luttrell Mining Company Inc → Chesney Surface Mine #3; 1982-01-01 to 1983-06-21; source msha-controller-operator-history
- **controller_controls_operator:** Preston Carroll Enterprises Inc → Luttrell Mining Company Inc; 1982-01-01 to 1983-06-21; source msha-controller-operator-history
- **operator_operates_mine:** Blue Ridge Mining Company Inc → Chesney Surface Mine #3; 1983-06-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Morrison Knudsen Corp (Old) → Chesney Surface Mine #3; 1983-06-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Morrison Knudsen Corp (Old) → Blue Ridge Mining Company Inc; 1983-06-22 to current/open; source msha-controller-operator-history