# Relationship history for MSHA mine 0404745

Current hierarchy: **Cheever R J → Lenwood Materials → Lenwood Materials**

- 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:** Cajon Materials & Services → Lenwood Materials; 1985-06-01 to 1986-10-28; source msha-controller-operator-history
- **controller_controls_mine:** Mathis Chester A → Lenwood Materials; 1985-06-01 to 1987-06-03; source msha-controller-operator-history
- **controller_controls_operator:** Mathis Chester A → Cajon Materials & Services; 1985-06-01 to 1986-10-28; source msha-controller-operator-history
- **operator_operates_mine:** M B Materials → Lenwood Materials; 1986-10-29 to 1989-06-20; source msha-controller-operator-history
- **controller_controls_mine:** Helberg John → Lenwood Materials; 1986-10-29 to 1989-06-20; source msha-controller-operator-history
- **controller_controls_operator:** Helberg John → M B Materials; 1986-10-29 to 1989-06-20; source msha-controller-operator-history
- **operator_operates_mine:** Lenwood Materials → Lenwood Materials; 1989-06-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cheever R J → Lenwood Materials; 1989-06-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cheever R J → Lenwood Materials; 1989-06-21 to current/open; source msha-controller-operator-history