# Relationship history for MSHA mine 4609376

Current hierarchy: **Alpha Metallurgical Resources Inc → Marfork Coal Company → Slip Ridge Contour**

- 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:** Massey Energy Company → Slip Ridge Contour; 1993-04-01 to 2011-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Marfork Coal Company → Slip Ridge Contour; 2010-12-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Marfork Coal Company; 2010-12-03 to 2011-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Alpha Natural Resources, Inc. → Slip Ridge Contour; 2011-06-01 to 2016-07-25; source msha-controller-operator-history
- **controller_controls_operator:** Alpha Natural Resources, Inc. → Marfork Coal Company; 2011-06-01 to 2016-07-25; source msha-controller-operator-history
- **controller_controls_mine:** Alpha Natural Resources Holdings, Inc → Slip Ridge Contour; 2016-07-26 to 2018-11-08; source msha-controller-operator-history
- **controller_controls_operator:** Alpha Natural Resources Holdings, Inc → Marfork Coal Company; 2016-07-26 to 2018-11-08; source msha-controller-operator-history
- **controller_controls_mine:** Alpha Metallurgical Resources Inc → Slip Ridge Contour; 2018-11-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alpha Metallurgical Resources Inc → Marfork Coal Company; 2018-11-09 to current/open; source msha-controller-operator-history