# Relationship history for MSHA mine 1515580

Current hierarchy: **Simpson Douglas--Eddie R Taylor → Rocky Branch Coal Company → No Rb #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:** Blanton David Deron → No Rb #1; 1984-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Double D Energy Inc → No Rb #1; 1986-04-01 to 1987-05-05; source msha-controller-operator-history
- **controller_controls_operator:** Blanton David Deron → Double D Energy Inc; 1986-04-01 to 1987-05-05; source msha-controller-operator-history
- **operator_operates_mine:** Burrow Mining Company Inc → No Rb #1; 1987-05-06 to 1987-09-22; source msha-controller-operator-history
- **controller_controls_mine:** Stephens Gary → No Rb #1; 1987-05-06 to 1987-09-22; source msha-controller-operator-history
- **controller_controls_operator:** Stephens Gary → Burrow Mining Company Inc; 1987-05-06 to 1987-09-22; source msha-controller-operator-history
- **operator_operates_mine:** L & L Coal Company → No Rb #1; 1987-09-23 to 1988-10-13; source msha-controller-operator-history
- **controller_controls_mine:** Lefevers Tim → No Rb #1; 1987-09-23 to 1988-10-13; source msha-controller-operator-history
- **controller_controls_operator:** Lefevers Tim → L & L Coal Company; 1987-09-23 to 1988-10-13; source msha-controller-operator-history
- **operator_operates_mine:** Rocky Branch Coal Company → No Rb #1; 1988-10-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Simpson Douglas--Eddie R Taylor Et Al → No Rb #1; 1988-10-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Simpson Douglas--Eddie R Taylor Et Al → Rocky Branch Coal Company; 1988-10-14 to current/open; source msha-controller-operator-history