# Relationship history for MSHA mine 1518454

Current hierarchy: **David  Leischman → Long Hole Augering Inc → LHA No. 19**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** G B  Hendrickson → LHA No. 19; 1986-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B & H Coal Co Inc → LHA No. 19; 2001-10-09 to 2019-10-31; source msha-controller-operator-history
- **controller_controls_operator:** G B  Hendrickson → B & H Coal Co Inc; 2001-10-09 to 2019-10-31; source msha-controller-operator-history
- **controller_controls_mine:** David  Leischman → LHA No. 19; 2018-08-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Long Hole Augering Inc → LHA No. 19; 2019-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Leischman → Long Hole Augering Inc; 2019-11-01 to current/open; source msha-controller-operator-history