# Relationship history for MSHA mine 2401457

Current hierarchy: **Navajo Transitional Energy Company LLC → Navajo Transitional Energy Company, LLC → Spring Creek 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

- **operator_operates_mine:** Spring Creek Coal Company → Spring Creek Mine; 1979-01-01 to 1993-06-01; source msha-controller-operator-history
- **controller_controls_mine:** MidAmerican Energy Holdings Company → Spring Creek Mine; 1979-01-01 to 1993-06-01; source msha-controller-operator-history
- **controller_controls_operator:** MidAmerican Energy Holdings Company → Spring Creek Coal Company; 1979-01-01 to 1993-06-01; source msha-controller-operator-history
- **operator_operates_mine:** Spring Creek Coal LLC → Spring Creek Mine; 1993-06-02 to 2019-10-24; source msha-controller-operator-history
- **controller_controls_mine:** RTZ-CRA Group → Spring Creek Mine; 1993-06-02 to 2009-11-19; source msha-controller-operator-history
- **controller_controls_operator:** RTZ-CRA Group → Spring Creek Coal LLC; 1993-06-02 to 2009-11-19; source msha-controller-operator-history
- **controller_controls_mine:** Cloud Peak Energy Resources LLC → Spring Creek Mine; 2009-11-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cloud Peak Energy Resources LLC → Spring Creek Coal LLC; 2009-11-20 to 2019-10-24; source msha-controller-operator-history
- **controller_controls_mine:** Navajo Nation → Spring Creek Mine; 2013-12-31 to 2019-10-24; source msha-controller-operator-history
- **operator_operates_mine:** Navajo Transitional Energy Company, LLC → Spring Creek Mine; 2019-10-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Navajo Nation → Navajo Transitional Energy Company, LLC; 2019-10-25 to 2019-10-24; source msha-controller-operator-history
- **controller_controls_mine:** Navajo Transitional Energy Company LLC → Spring Creek Mine; 2019-10-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Navajo Transitional Energy Company LLC → Navajo Transitional Energy Company, LLC; 2019-10-25 to current/open; source msha-controller-operator-history