# Relationship history for MSHA mine 3600154

Current hierarchy: **James River Limestone Company Inc → Benwood Limestone Company Inc → Lake Lynn Plant**

- 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:** Martin Marietta Aggregates → Lake Lynn Plant; 1950-01-01 to 1984-04-02; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Lake Lynn Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Aggregates; 1950-01-01 to 1984-04-02; source msha-controller-operator-history
- **controller_controls_mine:** James River Limestone Company Inc → Lake Lynn Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Benwood Limestone Company Inc → Lake Lynn Plant; 1984-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James River Limestone Company Inc → Benwood Limestone Company Inc; 1984-04-03 to current/open; source msha-controller-operator-history