# Relationship history for MSHA mine 3606472

Current hierarchy: **Immonen David J → Black Rock Exploration Company Inc → Brownsville**

- 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:** Cicconi Coal Company → Brownsville; 1977-08-01 to 1983-02-06; source msha-controller-operator-history
- **controller_controls_mine:** Cicconi Attilio → Brownsville; 1977-08-01 to 1983-02-06; source msha-controller-operator-history
- **controller_controls_operator:** Cicconi Attilio → Cicconi Coal Company; 1977-08-01 to 1983-02-06; source msha-controller-operator-history
- **operator_operates_mine:** Cicconi Coal Company → Brownsville; 1983-02-07 to 1990-05-20; source msha-controller-operator-history
- **controller_controls_mine:** Harasty Charles M → Brownsville; 1983-02-07 to 1990-05-20; source msha-controller-operator-history
- **controller_controls_operator:** Harasty Charles M → Cicconi Coal Company; 1983-02-07 to 1990-05-20; source msha-controller-operator-history
- **operator_operates_mine:** Black Rock Exploration Company Inc → Brownsville; 1990-05-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Immonen David J → Brownsville; 1990-05-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Immonen David J → Black Rock Exploration Company Inc; 1990-05-21 to current/open; source msha-controller-operator-history