# Relationship history for MSHA mine 2301082

Current hierarchy: **Marr John L - Jim E → Marr & Sons Construction Company → Boyd Quarry**

- 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:** Marr & Sons Construction Company → Boyd Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Marr John L - Jim E Et Al → Boyd Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Marr John L - Jim E Et Al → Marr & Sons Construction Company; 1950-01-01 to current/open; source msha-controller-operator-history