# Relationship history for MSHA mine 1700667

Current hierarchy: **Shawn  DeArmott → Plymouth Sand And Gravel → Plymouth Pit**

- 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:** Sebasticook Valley Concrete Inc → Plymouth Pit; 1999-05-01 to 2000-09-24; source msha-controller-operator-history
- **controller_controls_mine:** Philip A  Lander → Plymouth Pit; 1999-05-01 to 2000-09-24; source msha-controller-operator-history
- **controller_controls_operator:** Philip A  Lander → Sebasticook Valley Concrete Inc; 1999-05-01 to 2000-09-24; source msha-controller-operator-history
- **operator_operates_mine:** Plymouth Sand And Gravel → Plymouth Pit; 2000-09-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Shawn  DeArmott → Plymouth Pit; 2000-09-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shawn  DeArmott → Plymouth Sand And Gravel; 2000-09-25 to current/open; source msha-controller-operator-history