# Relationship history for MSHA mine 0404149

Current hierarchy: **Jens  Karlshoej → Nordic Industries Inc → Parks Bar 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Emery  Conrad → Parks Bar Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Axel  Karlshoej → Parks Bar Quarry; 1950-01-01 to 2012-10-08; source msha-controller-operator-history
- **operator_operates_mine:** Claude C Wood Company → Parks Bar Quarry; 1978-03-09 to 1987-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Emery  Conrad → Claude C Wood Company; 1978-03-09 to 1987-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Al Johnson Construction Company → Parks Bar Quarry; 1984-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Claude C Wood Company → Parks Bar Quarry; 1988-01-01 to 1993-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Al Johnson Construction Company → Claude C Wood Company; 1988-01-01 to 1993-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Nordic Industries Inc → Parks Bar Quarry; 1994-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Axel  Karlshoej → Nordic Industries Inc; 1994-01-01 to 2012-10-08; source msha-controller-operator-history
- **controller_controls_mine:** Jens  Karlshoej → Parks Bar Quarry; 2012-10-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jens  Karlshoej → Nordic Industries Inc; 2012-10-09 to current/open; source msha-controller-operator-history