# Relationship history for MSHA mine 4800997

Current hierarchy: **Arch Resources Inc → Jacobs Ranch Coal LLC → Jacobs Ranch 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Kerr McGee Corp → Jacobs Ranch Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kerr-Mc Gee Coal Corp → Jacobs Ranch Mine; 1975-01-01 to 1998-09-08; source msha-controller-operator-history
- **controller_controls_operator:** Kerr McGee Corp → Kerr-Mc Gee Coal Corp; 1975-01-01 to 1998-09-08; source msha-controller-operator-history
- **operator_operates_mine:** Jacobs Ranch Coal LLC → Jacobs Ranch Mine; 1998-09-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** RTZ-CRA Group → Jacobs Ranch Mine; 1998-09-09 to 2009-09-30; source msha-controller-operator-history
- **controller_controls_operator:** RTZ-CRA Group → Jacobs Ranch Coal LLC; 1998-09-09 to 2009-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Arch Resources Inc → Jacobs Ranch Mine; 2009-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Arch Resources Inc → Jacobs Ranch Coal LLC; 2009-10-01 to current/open; source msha-controller-operator-history