# Relationship history for MSHA mine 4002131

Current hierarchy: **Technical Service Inc → B M & M Services Inc → No 1 Surface**

- 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:** Tennessee Mining Company → No 1 Surface; 1976-10-01 to 1977-08-07; source msha-controller-operator-history
- **controller_controls_mine:** Slone Dan → No 1 Surface; 1976-10-01 to 1977-08-07; source msha-controller-operator-history
- **controller_controls_operator:** Slone Dan → Tennessee Mining Company; 1976-10-01 to 1977-08-07; source msha-controller-operator-history
- **operator_operates_mine:** B M & M Services Inc → No 1 Surface; 1977-08-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Technical Service Inc → No 1 Surface; 1977-08-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Technical Service Inc → B M & M Services Inc; 1977-08-08 to current/open; source msha-controller-operator-history