# Relationship history for MSHA mine 4800086

Current hierarchy: **Kemmerer Holdings LLC → Kemmerer Operations, LLC → Kemmerer 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:** Chevron Corporation → Kemmerer Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kemmerer Coal Company → Kemmerer Mine; 1971-08-01 to 1981-09-08; source msha-controller-operator-history
- **controller_controls_mine:** Lincoln Corporation → Kemmerer Mine; 1971-08-01 to 1981-09-24; source msha-controller-operator-history
- **controller_controls_operator:** Lincoln Corporation → Kemmerer Coal Company; 1971-08-01 to 1981-09-08; source msha-controller-operator-history
- **operator_operates_mine:** Chevron Mining Inc → Kemmerer Mine; 1981-09-09 to 2012-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Chevron Corporation → Chevron Mining Inc; 1981-09-09 to 2012-01-31; source msha-controller-operator-history
- **operator_operates_mine:** Westmoreland Kemmerer, LLC → Kemmerer Mine; 2012-02-01 to 2019-06-19; source msha-controller-operator-history
- **controller_controls_mine:** Westmoreland Coal Company → Kemmerer Mine; 2012-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Westmoreland Coal Company → Westmoreland Kemmerer, LLC; 2012-02-01 to 2019-06-19; source msha-controller-operator-history
- **operator_operates_mine:** Kemmerer Operations, LLC → Kemmerer Mine; 2019-06-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kemmerer Holdings LLC → Kemmerer Mine; 2019-06-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kemmerer Holdings LLC → Kemmerer Operations, LLC; 2019-06-20 to current/open; source msha-controller-operator-history