# Relationship history for MSHA mine 3606541

Current hierarchy: **Pazzalia Richard → Pazzalia Coal Company Inc → Keyser Avenue Breaker**

- 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

- **operator_operates_mine:** Panther Valley Mining & Construction Co Ltd → Keyser Avenue Breaker; 1977-10-01 to 1978-03-29; source msha-controller-operator-history
- **controller_controls_mine:** Raymond Donald J & Eric Schramm → Keyser Avenue Breaker; 1977-10-01 to 1978-03-29; source msha-controller-operator-history
- **controller_controls_operator:** Raymond Donald J & Eric Schramm → Panther Valley Mining & Construction Co Ltd; 1977-10-01 to 1978-03-29; source msha-controller-operator-history
- **operator_operates_mine:** Marvin Enterprises Inc → Keyser Avenue Breaker; 1978-03-30 to 1979-06-04; source msha-controller-operator-history
- **controller_controls_mine:** Metallo Mary Lou → Keyser Avenue Breaker; 1978-03-30 to 1979-06-04; source msha-controller-operator-history
- **controller_controls_operator:** Metallo Mary Lou → Marvin Enterprises Inc; 1978-03-30 to 1979-06-04; source msha-controller-operator-history
- **operator_operates_mine:** Pazzalia Coal Company Inc → Keyser Avenue Breaker; 1979-06-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Pazzalia Richard → Keyser Avenue Breaker; 1979-06-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pazzalia Richard → Pazzalia Coal Company Inc; 1979-06-05 to current/open; source msha-controller-operator-history