# Relationship history for MSHA mine 1800681

Current hierarchy: **David J  Stewart → York Building Products Co Inc. → Cecil Plant**

- 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 → Cecil Plant; 1950-01-01 to 2022-09-08; source msha-controller-operator-history
- **operator_operates_mine:** Mid-Atlantic Sand & Gravel Company Inc → Cecil Plant; 1980-12-01 to 1983-09-25; source msha-controller-operator-history
- **controller_controls_mine:** Arthur D  Johnston → Cecil Plant; 1980-12-01 to 1983-09-25; source msha-controller-operator-history
- **controller_controls_operator:** Arthur D  Johnston → Mid-Atlantic Sand & Gravel Company Inc; 1980-12-01 to 1983-09-25; source msha-controller-operator-history
- **operator_operates_mine:** Brandywine Sand & Gravel → Cecil Plant; 1983-09-26 to 1987-04-07; source msha-controller-operator-history
- **controller_controls_mine:** Columbia Enterprises Inc → Cecil Plant; 1983-09-26 to 1987-04-07; source msha-controller-operator-history
- **controller_controls_operator:** Columbia Enterprises Inc → Brandywine Sand & Gravel; 1983-09-26 to 1987-04-07; source msha-controller-operator-history
- **operator_operates_mine:** Cecil Sand & Gravel Inc → Cecil Plant; 1987-04-08 to 2002-03-20; source msha-controller-operator-history
- **controller_controls_mine:** Michael K  Jones  et al → Cecil Plant; 1987-04-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael K  Jones  et al → Cecil Sand & Gravel Inc; 1987-04-08 to 2002-03-20; source msha-controller-operator-history
- **operator_operates_mine:** York Building Products Co Inc. → Cecil Plant; 2002-03-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert H Stewart III et al → York Building Products Co Inc.; 2002-03-21 to 2022-09-08; source msha-controller-operator-history
- **controller_controls_mine:** David J  Stewart → Cecil Plant; 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