# Relationship history for MSHA mine 1600522

Current hierarchy: **Ruth L  Mahler → Trail Construction Company Inc → Talley 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:** Dial Gravel Company → Talley Pit; 1950-01-01 to 1980-04-22; source msha-controller-operator-history
- **controller_controls_mine:** Dial K W → Talley Pit; 1950-01-01 to 1980-04-22; source msha-controller-operator-history
- **controller_controls_operator:** Dial K W → Dial Gravel Company; 1950-01-01 to 1980-04-22; source msha-controller-operator-history
- **controller_controls_mine:** Ruth L  Mahler → Talley Pit; 1979-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sun Industries → Talley Pit; 1980-04-23 to 1981-10-13; source msha-controller-operator-history
- **controller_controls_mine:** Robinson Burnell → Talley Pit; 1980-04-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robinson Burnell → Sun Industries; 1980-04-23 to 1981-10-13; source msha-controller-operator-history
- **operator_operates_mine:** Trail Construction Company Inc → Talley Pit; 1981-10-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ruth L  Mahler → Trail Construction Company Inc; 1981-10-14 to current/open; source msha-controller-operator-history