# Relationship history for MSHA mine 3002426

Current hierarchy: **David J  Dalrymple → Dalrymple Gravel & Contracting Co Inc → Coopers Plains Pit**

- 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:** Koppers Company Inc → Coopers Plains Pit; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Dalrymple Holding Corp → Coopers Plains Pit; 1950-01-01 to 2014-10-17; source msha-controller-operator-history
- **operator_operates_mine:** Lycoming Silica Sand Company → Coopers Plains Pit; 1979-01-01 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Company Inc → Lycoming Silica Sand Company; 1979-01-01 to 1988-11-13; source msha-controller-operator-history
- **operator_operates_mine:** General Crushed Stone Company → Coopers Plains Pit; 1988-11-14 to 1996-04-22; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Coopers Plains Pit; 1988-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → General Crushed Stone Company; 1988-11-14 to 1996-04-22; source msha-controller-operator-history
- **operator_operates_mine:** Scl Ventures L L C → Coopers Plains Pit; 1996-04-23 to 2002-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Martin A  Galasso et al → Coopers Plains Pit; 1996-04-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin A  Galasso et al → Scl Ventures L L C; 1996-04-23 to 2002-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Tom  Longe et al → Scl Ventures L L C; 1996-04-23 to 2002-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Dalrymple Gravel & Contracting Co Inc → Coopers Plains Pit; 2003-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dalrymple Holding Corp → Dalrymple Gravel & Contracting Co Inc; 2003-01-01 to 2014-10-17; source msha-controller-operator-history
- **controller_controls_mine:** David J  Dalrymple → Coopers Plains Pit; 2014-10-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David J  Dalrymple → Dalrymple Gravel & Contracting Co Inc; 2014-10-18 to current/open; source msha-controller-operator-history