# Relationship history for MSHA mine 4607449

Current hierarchy: **Keen Larry R → Keenco Coal Corp → No 3**

- 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:** John  Lingerfelt → No 3; 1987-08-18 to 1993-05-11; source msha-controller-operator-history
- **operator_operates_mine:** Desperado Coal Company Inc → No 3; 1988-02-01 to 1988-09-01; source msha-controller-operator-history
- **controller_controls_mine:** Brooks Michael G → No 3; 1988-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brooks Michael G → Desperado Coal Company Inc; 1988-02-01 to 1988-09-01; source msha-controller-operator-history
- **operator_operates_mine:** Kerz Coal Corp → No 3; 1988-09-02 to 1993-05-11; source msha-controller-operator-history
- **controller_controls_operator:** John  Lingerfelt → Kerz Coal Corp; 1988-09-02 to 1993-05-11; source msha-controller-operator-history
- **controller_controls_mine:** Keen Larry R → No 3; 1992-10-22 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Keenco Coal Corp → No 3; 1993-05-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Keen Larry R → Keenco Coal Corp; 1993-05-12 to current/open; source msha-controller-operator-history