# Relationship history for MSHA mine 3401156

Current hierarchy: **Jacobson Dean → L A Jacobson Inc → JACOBSON SAND PL**

- 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:** L A Jacobson Inc → JACOBSON SAND PL; 1978-12-01 to 1988-10-11; source msha-controller-operator-history
- **controller_controls_mine:** Jacobson Gayle M → JACOBSON SAND PL; 1978-12-01 to 1988-10-11; source msha-controller-operator-history
- **controller_controls_operator:** Jacobson Gayle M → L A Jacobson Inc; 1978-12-01 to 1988-10-11; source msha-controller-operator-history
- **operator_operates_mine:** L A Jacobson Inc → JACOBSON SAND PL; 1988-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jacobson Dean → JACOBSON SAND PL; 1988-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jacobson Dean → L A Jacobson Inc; 1988-10-12 to current/open; source msha-controller-operator-history