# Relationship history for MSHA mine 1517892

Current hierarchy: **Donn A  Chickering → Branham & Baker Underground Corp → Marine #1**

- 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:** Marine Coal Corp → Marine #1; 1997-01-01 to 1997-06-30; source msha-controller-operator-history
- **controller_controls_mine:** (Donald) Todd  Kiscaden et al → Marine #1; 1997-01-01 to 1997-06-30; source msha-controller-operator-history
- **controller_controls_operator:** (Donald) Todd  Kiscaden et al → Marine Coal Corp; 1997-01-01 to 1997-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Branham & Baker Underground Corp → Marine #1; 1997-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Donn A  Chickering → Marine #1; 1997-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donn A  Chickering → Branham & Baker Underground Corp; 1997-07-01 to current/open; source msha-controller-operator-history