# Relationship history for MSHA mine 2900659

Current hierarchy: **Tree Doctors → Tree Doctors → Black Diamond Strip**

- 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:** Black Diamond Coal Corp → Black Diamond Strip; 1950-01-01 to 1974-10-01; source msha-controller-operator-history
- **controller_controls_mine:** Black Diamond Coal Corp → Black Diamond Strip; 1950-01-01 to 1974-10-01; source msha-controller-operator-history
- **controller_controls_operator:** Black Diamond Coal Corp → Black Diamond Coal Corp; 1950-01-01 to 1974-10-01; source msha-controller-operator-history
- **operator_operates_mine:** Tree Doctors → Black Diamond Strip; 1974-10-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tree Doctors → Black Diamond Strip; 1974-10-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tree Doctors → Tree Doctors; 1974-10-02 to current/open; source msha-controller-operator-history