# Relationship history for MSHA mine 3607045

Current hierarchy: **NSM PLC → Rox Coal Inc → Barbara #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:** Hawkview Mining Corp → Barbara #1; 1980-10-01 to 1989-07-14; source msha-controller-operator-history
- **controller_controls_mine:** Lange Ulrich O → Barbara #1; 1980-10-01 to 1989-07-14; source msha-controller-operator-history
- **controller_controls_operator:** Lange Ulrich O → Hawkview Mining Corp; 1980-10-01 to 1989-07-14; source msha-controller-operator-history
- **operator_operates_mine:** Hawkview Mining Corp → Barbara #1; 1989-07-15 to 1990-06-17; source msha-controller-operator-history
- **controller_controls_mine:** Edward E  Smock → Barbara #1; 1989-07-15 to 1990-06-17; source msha-controller-operator-history
- **controller_controls_operator:** Edward E  Smock → Hawkview Mining Corp; 1989-07-15 to 1990-06-17; source msha-controller-operator-history
- **operator_operates_mine:** Rox Coal Inc → Barbara #1; 1990-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** NSM PLC → Barbara #1; 1990-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** NSM PLC → Rox Coal Inc; 1990-06-18 to current/open; source msha-controller-operator-history