# Relationship history for MSHA mine 3600243

Current hierarchy: **A Ross  Myers → Allan Myers Materials → Cedar Hill 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:** D M Stoltzfus → Cedar Hill Quarry; 1950-01-01 to 2007-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Ruth E  Stoltzfus → Cedar Hill Quarry; 1950-01-01 to 2006-05-08; source msha-controller-operator-history
- **controller_controls_operator:** Ruth E  Stoltzfus → D M Stoltzfus; 1950-01-01 to 2006-05-08; source msha-controller-operator-history
- **controller_controls_mine:** A Ross  Myers → Cedar Hill Quarry; 2006-05-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** A Ross  Myers → D M Stoltzfus; 2006-05-09 to 2007-05-31; source msha-controller-operator-history
- **operator_operates_mine:** ICM of Maryland Inc → Cedar Hill Quarry; 2007-06-01 to 2015-06-21; source msha-controller-operator-history
- **controller_controls_mine:** A Ross  Myers → Cedar Hill Quarry; 2007-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** A Ross  Myers → ICM of Maryland Inc; 2007-06-01 to 2015-06-21; source msha-controller-operator-history
- **operator_operates_mine:** Allan Myers Materials → Cedar Hill Quarry; 2015-06-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** A Ross  Myers → Allan Myers Materials; 2015-06-22 to current/open; source msha-controller-operator-history