# Relationship history for MSHA mine 1800812

Current hierarchy: **David J  Stewart → York Building Products Co Inc → Principio 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

- **controller_controls_mine:** Robert H Stewart III et al → Principio Quarry; 1950-01-01 to 2022-09-08; source msha-controller-operator-history
- **operator_operates_mine:** York Building Products Co Inc → Principio Quarry; 2021-08-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert H Stewart III et al → York Building Products Co Inc; 2021-08-31 to 2022-09-08; source msha-controller-operator-history
- **controller_controls_mine:** David J  Stewart → Principio Quarry; 2022-09-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David J  Stewart → York Building Products Co Inc; 2022-09-09 to current/open; source msha-controller-operator-history