# Relationship history for MSHA mine 0900929

Current hierarchy: **Robbie M  Worley → Twi-Lite Blue Quarry, Inc. → TWILITE BLUE 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** T & C Quarries Inc → TWILITE BLUE QUARRY; 1980-09-01 to 2005-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Robbie M  Worley → TWILITE BLUE QUARRY; 1980-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robbie M  Worley → T & C Quarries Inc; 1980-09-01 to 2005-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Twi-Lite Blue Quarry, Inc. → TWILITE BLUE QUARRY; 2006-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robbie M  Worley → TWILITE BLUE QUARRY; 2006-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robbie M  Worley → Twi-Lite Blue Quarry, Inc.; 2006-01-01 to current/open; source msha-controller-operator-history