# Relationship history for MSHA mine 4606880

Current hierarchy: **Alpha Metallurgical Resources Inc → Power Mountain Contura LLC → Power Mountain Processing**

- 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:** Bethlehem Steel Corp → Power Mountain Processing; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Beth Energy Mines Inc → Power Mountain Processing; 1985-01-01 to 1997-10-15; source msha-controller-operator-history
- **controller_controls_operator:** Bethlehem Steel Corp → Beth Energy Mines Inc; 1985-01-01 to 1997-10-15; source msha-controller-operator-history
- **operator_operates_mine:** Power Mountain Coal Company → Power Mountain Processing; 1997-10-16 to 2016-07-25; source msha-controller-operator-history
- **controller_controls_mine:** Massey Energy Company → Power Mountain Processing; 1997-10-16 to 2011-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Power Mountain Coal Company; 1997-10-16 to 2011-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Alpha Natural Resources, Inc. → Power Mountain Processing; 2011-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alpha Natural Resources, Inc. → Power Mountain Coal Company; 2011-06-01 to 2016-07-25; source msha-controller-operator-history
- **operator_operates_mine:** Power Mountain Contura LLC → Power Mountain Processing; 2016-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Alpha Metallurgical Resources Inc → Power Mountain Processing; 2016-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alpha Metallurgical Resources Inc → Power Mountain Contura LLC; 2016-07-26 to current/open; source msha-controller-operator-history