# Relationship history for MSHA mine 4405309

Current hierarchy: **Dennis Allen  Ramey → Sweatbee Coal Company → No 2**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Rick A  Matney  et al → No 2; 1978-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tri-M Coal Company → No 2; 1979-10-01 to 1987-04-09; source msha-controller-operator-history
- **controller_controls_operator:** Rick A  Matney  et al → Tri-M Coal Company; 1979-10-01 to 1987-04-09; source msha-controller-operator-history
- **controller_controls_operator:** Hank K  Matney  et al → Tri-M Coal Company; 1979-10-01 to 1987-04-09; source msha-controller-operator-history
- **controller_controls_operator:** Fred D  Matney  et al → Tri-M Coal Company; 1979-10-01 to 1987-04-09; source msha-controller-operator-history
- **controller_controls_mine:** Dennis Allen  Ramey → No 2; 1980-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sweatbee Coal Company → No 2; 1987-04-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dennis Allen  Ramey → Sweatbee Coal Company; 1987-04-10 to current/open; source msha-controller-operator-history