# Relationship history for MSHA mine 3607212

Current hierarchy: **Bone Shirley → George Bone Construction → Leadville Plant**

- 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:** Anthracite Resources → Leadville Plant; 1981-09-01 to 1986-08-07; source msha-controller-operator-history
- **controller_controls_mine:** Bone George → Leadville Plant; 1981-09-01 to 1994-05-01; source msha-controller-operator-history
- **controller_controls_operator:** Bone George → Anthracite Resources; 1981-09-01 to 1986-08-07; source msha-controller-operator-history
- **controller_controls_mine:** Bechtel William → Leadville Plant; 1986-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** A B C Coal Company Inc → Leadville Plant; 1986-08-08 to 1992-04-09; source msha-controller-operator-history
- **controller_controls_operator:** Bechtel William → A B C Coal Company Inc; 1986-08-08 to 1992-04-09; source msha-controller-operator-history
- **controller_controls_mine:** Michael G  Faleski → Leadville Plant; 1991-06-01 to 1994-02-20; source msha-controller-operator-history
- **operator_operates_mine:** Laurel Run Corp → Leadville Plant; 1992-04-10 to 1994-02-20; source msha-controller-operator-history
- **controller_controls_operator:** Michael G  Faleski → Laurel Run Corp; 1992-04-10 to 1994-02-20; source msha-controller-operator-history
- **operator_operates_mine:** New County Coal Company → Leadville Plant; 1994-02-21 to 1996-05-05; source msha-controller-operator-history
- **controller_controls_mine:** Albert George & Michael Keklak → Leadville Plant; 1994-02-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Albert George & Michael Keklak → New County Coal Company; 1994-02-21 to 1996-05-05; source msha-controller-operator-history
- **operator_operates_mine:** George Bone Construction → Leadville Plant; 1996-05-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bone Shirley → Leadville Plant; 1996-05-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bone Shirley → George Bone Construction; 1996-05-06 to current/open; source msha-controller-operator-history