# Relationship history for MSHA mine 1518700

Current hierarchy: **Leonard  Hendrickson → Hendrickson Drilling LLC → Auger Mine No 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

- **controller_controls_mine:** G B  Hendrickson → Auger Mine No 1; 1986-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B & H Coal Co Inc → Auger Mine No 1; 2004-01-05 to 2011-11-16; source msha-controller-operator-history
- **controller_controls_operator:** G B  Hendrickson → B & H Coal Co Inc; 2004-01-05 to 2011-11-16; source msha-controller-operator-history
- **controller_controls_mine:** Robert  Hendrickson et al → Auger Mine No 1; 2004-12-30 to 2010-04-22; source msha-controller-operator-history
- **controller_controls_mine:** Leonard  Hendrickson → Auger Mine No 1; 2010-04-23 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hendrickson Drilling LLC → Auger Mine No 1; 2011-11-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Hendrickson et al → Hendrickson Drilling LLC; 2011-11-17 to 2010-04-22; source msha-controller-operator-history
- **controller_controls_operator:** Leonard  Hendrickson et al → Hendrickson Drilling LLC; 2011-11-17 to 2010-04-22; source msha-controller-operator-history
- **controller_controls_operator:** Leonard  Hendrickson → Hendrickson Drilling LLC; 2011-11-17 to current/open; source msha-controller-operator-history