# Relationship history for MSHA mine 4201490

Current hierarchy: **Harper H L → Harper Mining Company → Mockingbird Mine**

- 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

- **controller_controls_mine:** J & R Mining Company → Mockingbird Mine; 1950-01-01 to 1980-03-31; source msha-controller-operator-history
- **operator_operates_mine:** J & R Mining Company → Mockingbird Mine; 1978-03-09 to 1980-03-31; source msha-controller-operator-history
- **controller_controls_operator:** J & R Mining Company → J & R Mining Company; 1978-03-09 to 1980-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Harper H L → Mockingbird Mine; 1978-03-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Harper Mining Company → Mockingbird Mine; 1980-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harper H L → Harper Mining Company; 1980-04-01 to current/open; source msha-controller-operator-history