# Relationship history for MSHA mine 1505337

Current hierarchy: **Blackhawk Mining LLC → Black Hawk Mining LLC → Black Hawk Refuse Site #1**

- 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

- **operator_operates_mine:** Island Creek Coal Company → Black Hawk Refuse Site #1; 1950-01-01 to 1991-05-19; source msha-controller-operator-history
- **controller_controls_mine:** Occidental Petroleum Corp → Black Hawk Refuse Site #1; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Occidental Petroleum Corp → Island Creek Coal Company; 1950-01-01 to 1991-05-19; source msha-controller-operator-history
- **operator_operates_mine:** Buck Coal Inc → Black Hawk Refuse Site #1; 1991-05-20 to 1995-07-23; source msha-controller-operator-history
- **controller_controls_mine:** Tredegar Industries Inc → Black Hawk Refuse Site #1; 1991-05-20 to 1995-07-23; source msha-controller-operator-history
- **controller_controls_operator:** Tredegar Industries Inc → Buck Coal Inc; 1991-05-20 to 1995-07-23; source msha-controller-operator-history
- **controller_controls_mine:** John  Harris → Black Hawk Refuse Site #1; 1992-10-28 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bull Creek Coal Corporation → Black Hawk Refuse Site #1; 1995-07-24 to 2010-07-11; source msha-controller-operator-history
- **controller_controls_operator:** John  Harris → Bull Creek Coal Corporation; 1995-07-24 to 2010-07-11; source msha-controller-operator-history
- **operator_operates_mine:** Black Hawk Mining LLC → Black Hawk Refuse Site #1; 2010-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thomas A  Potter et al → Black Hawk Refuse Site #1; 2010-07-16 to 2013-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Thomas A  Potter et al → Black Hawk Mining LLC; 2010-07-16 to 2013-06-30; source msha-controller-operator-history
- **controller_controls_operator:** John M  Potter et al → Black Hawk Mining LLC; 2010-07-16 to 2013-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Blackhawk Mining LLC → Black Hawk Refuse Site #1; 2013-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blackhawk Mining LLC → Black Hawk Mining LLC; 2013-07-01 to current/open; source msha-controller-operator-history