# Relationship history for MSHA mine 4002950

Current hierarchy: **Daugherty Leona → L & L Coal Company Inc → #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

- **controller_controls_mine:** Daugherty Leona Et Al → #1; 1984-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Westbourne Mining Company → #1; 1987-05-01 to 1987-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Muse Zie Et Al → #1; 1987-05-01 to 1987-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Muse Zie Et Al → Westbourne Mining Company; 1987-05-01 to 1987-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Little Duff Coal Company → #1; 1987-09-01 to 1988-06-20; source msha-controller-operator-history
- **controller_controls_mine:** Campbell John → #1; 1987-09-01 to 1988-06-20; source msha-controller-operator-history
- **controller_controls_operator:** Campbell John → Little Duff Coal Company; 1987-09-01 to 1988-06-20; source msha-controller-operator-history
- **operator_operates_mine:** L & L Coal Company Inc → #1; 1988-06-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Daugherty Leona Et Al → L & L Coal Company Inc; 1988-06-21 to current/open; source msha-controller-operator-history