# Relationship history for MSHA mine 3600512

Current hierarchy: **James W  Knorr → Knorr Contracting Inc → Mausdale 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:** Lycoming Silica Sand Company → Mausdale Quarry; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Koppers Company Inc → Mausdale Quarry; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Company Inc → Lycoming Silica Sand Company; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Aggregates Pennsylvania Inc → Mausdale Quarry; 1988-11-14 to 2007-01-07; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Mausdale Quarry; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Hanson Aggregates Pennsylvania Inc; 1988-11-14 to 2007-01-07; source msha-controller-operator-history
- **operator_operates_mine:** Knorr Contracting Inc → Mausdale Quarry; 2007-01-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James W  Knorr → Mausdale Quarry; 2007-01-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James W  Knorr → Knorr Contracting Inc; 2007-01-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Mausdale Quarry; 2007-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Hanson Aggregates Pennsylvania Inc; 2007-08-23 to 2007-01-07; source msha-controller-operator-history