# Relationship history for MSHA mine 1511976

Current hierarchy: **Riggs Bobby → Riggs Mining Company Inc → Mine No 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:** Donnie T  Hoskins et al → Mine No 1; 1977-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Trent Coal Company → Mine No 1; 1979-07-01 to 1980-03-29; source msha-controller-operator-history
- **controller_controls_operator:** Donnie T  Hoskins et al → Trent Coal Company; 1979-07-01 to 1980-03-29; source msha-controller-operator-history
- **operator_operates_mine:** Riggs Mining Company Inc → Mine No 1; 1980-03-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Riggs Bobby → Mine No 1; 1980-03-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Riggs Bobby → Riggs Mining Company Inc; 1980-03-30 to current/open; source msha-controller-operator-history