# Relationship history for MSHA mine 0404760

Current hierarchy: **Adams Mike & Fred Ellrott → Cajon Pass Sand & Gravel → Cajon Pass 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

- **controller_controls_mine:** Mathis Chester A → Cajon Pass Sand & Gravel; 1985-06-01 to 1987-06-03; source msha-controller-operator-history
- **operator_operates_mine:** Cajon Materials & Services → Cajon Pass Sand & Gravel; 1985-08-01 to 1987-06-03; source msha-controller-operator-history
- **controller_controls_operator:** Mathis Chester A → Cajon Materials & Services; 1985-08-01 to 1987-06-03; source msha-controller-operator-history
- **operator_operates_mine:** Dni Materials Inc → Cajon Pass Sand & Gravel; 1987-06-04 to 1989-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Wayne  Dougherty → Cajon Pass Sand & Gravel; 1987-06-04 to 1989-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Wayne  Dougherty → Dni Materials Inc; 1987-06-04 to 1989-07-31; source msha-controller-operator-history
- **operator_operates_mine:** Cajon Pass Sand & Gravel → Cajon Pass Sand & Gravel; 1989-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Adams Mike & Fred Ellrott → Cajon Pass Sand & Gravel; 1989-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Adams Mike & Fred Ellrott → Cajon Pass Sand & Gravel; 1989-08-01 to current/open; source msha-controller-operator-history