# Relationship history for MSHA mine 3900806

Current hierarchy: **Julius Terry → J & J Construction → Matson Pit**

- 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:** H & L Johnson Sand & Gravel → Matson Pit; 1950-01-01 to 1985-05-06; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Harold → Matson Pit; 1950-01-01 to 1985-05-06; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Harold → H & L Johnson Sand & Gravel; 1950-01-01 to 1985-05-06; source msha-controller-operator-history
- **operator_operates_mine:** Hofer Construction → Matson Pit; 1985-05-07 to 1986-12-26; source msha-controller-operator-history
- **controller_controls_mine:** Hofer Kathryn J → Matson Pit; 1985-05-07 to 1986-12-26; source msha-controller-operator-history
- **controller_controls_operator:** Hofer Kathryn J → Hofer Construction; 1985-05-07 to 1986-12-26; source msha-controller-operator-history
- **operator_operates_mine:** J & J Construction → Matson Pit; 1986-12-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Julius Terry → Matson Pit; 1986-12-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Julius Terry → J & J Construction; 1986-12-27 to current/open; source msha-controller-operator-history