# Relationship history for MSHA mine 3901218

Current hierarchy: **Robert L  Anderson → Anderson Construction → Frehreick 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:** Anderson Construction → Frehreick Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert L  Anderson → Frehreick Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert L  Anderson → Anderson Construction; 1979-01-01 to current/open; source msha-controller-operator-history