# Relationship history for MSHA mine 2800001

Current hierarchy: **Roger  Mahan; Gary  Mahan → Riverdale Quarry LLC → Riverdale 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:** Riverdale Quarry Company → Riverdale Quarry; 1950-01-01 to 1995-04-05; source msha-controller-operator-history
- **controller_controls_mine:** Robert  Hess → Riverdale Quarry; 1950-01-01 to 1995-04-05; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Hess → Riverdale Quarry Company; 1950-01-01 to 1995-04-05; source msha-controller-operator-history
- **operator_operates_mine:** Riverdale Quarry Llc → Riverdale Quarry; 1995-04-06 to 1999-06-30; source msha-controller-operator-history
- **controller_controls_mine:** 287 Associates Llc et al → Riverdale Quarry; 1995-04-06 to 1999-06-30; source msha-controller-operator-history
- **controller_controls_operator:** 287 Associates Llc et al → Riverdale Quarry Llc; 1995-04-06 to 1999-06-30; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Riverdale Quarry; 1996-09-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tilcon New York Inc → Riverdale Quarry; 1999-07-01 to 2025-04-14; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Tilcon New York Inc; 1999-07-01 to 2025-04-14; source msha-controller-operator-history
- **operator_operates_mine:** Riverdale Quarry LLC → Riverdale Quarry; 2025-04-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gary  Mahan et al → Riverdale Quarry; 2025-04-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary  Mahan et al → Riverdale Quarry LLC; 2025-04-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roger  Mahan et al → Riverdale Quarry LLC; 2025-04-15 to current/open; source msha-controller-operator-history