# Relationship history for MSHA mine 4402776

Current hierarchy: **Doug  Dalton → Holston River Quarry Inc → Newbern 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

- **operator_operates_mine:** Radford Limestone Corp → Newbern Plant; 1950-01-01 to 1988-04-19; source msha-controller-operator-history
- **controller_controls_mine:** Troitino Thomas R → Newbern Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Troitino Thomas R → Radford Limestone Corp; 1950-01-01 to 1988-04-19; source msha-controller-operator-history
- **controller_controls_mine:** Doug  Dalton → Newbern Plant; 1980-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Holston River Quarry Inc → Newbern Plant; 1988-04-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Doug  Dalton → Holston River Quarry Inc; 1988-04-20 to current/open; source msha-controller-operator-history