# Relationship history for MSHA mine 0503017

Current hierarchy: **Cyprus Amax Minerals Company → Empire Energy Corp → Eagle No 9 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:** Houston Natural Gas Corp → Eagle No 9 Mine; 1976-07-01 to 1980-04-02; source msha-controller-operator-history
- **operator_operates_mine:** Empire Energy Corp → Eagle No 9 Mine; 1977-01-01 to 1980-03-14; source msha-controller-operator-history
- **controller_controls_operator:** Houston Natural Gas Corp → Empire Energy Corp; 1977-01-01 to 1980-03-14; source msha-controller-operator-history
- **operator_operates_mine:** Empire Energy Corp → Eagle No 9 Mine; 1980-03-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Amax Minerals Company → Eagle No 9 Mine; 1980-03-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Amax Minerals Company → Empire Energy Corp; 1980-03-15 to current/open; source msha-controller-operator-history