# Relationship history for MSHA mine 1512042

Current hierarchy: **Horizon Natural Resources Incorporated → Addwest Mining Inc → Mine No 4**

- 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:** Horizon Natural Resources Incorporated → Mine No 4; 1978-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Pyramid Mining Inc → Mine No 4; 1979-10-01 to 1983-02-22; source msha-controller-operator-history
- **controller_controls_operator:** Horizon Natural Resources Incorporated → Pyramid Mining Inc; 1979-10-01 to 1983-02-22; source msha-controller-operator-history
- **operator_operates_mine:** Pyramid Mining Inc → Mine No 4; 1983-02-23 to 1989-04-11; source msha-controller-operator-history
- **controller_controls_mine:** First Mississippi Corp → Mine No 4; 1983-02-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** First Mississippi Corp → Pyramid Mining Inc; 1983-02-23 to 1989-04-11; source msha-controller-operator-history
- **controller_controls_mine:** Horizon Natural Resources Incorporated → Mine No 4; 1986-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Addwest Mining Inc → Mine No 4; 1989-04-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Horizon Natural Resources Incorporated → Addwest Mining Inc; 1989-04-12 to current/open; source msha-controller-operator-history