# Relationship history for MSHA mine 4300552

Current hierarchy: **Harvey M  Plimpton; Harvey M  Plimpton Jr → Plimpton Excavating LLC → Extec 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:** Harvey Plimpton Construction → Extec Plant; 2000-10-01 to 2016-04-05; source msha-controller-operator-history
- **controller_controls_mine:** Harvey  Plimpton → Extec Plant; 2000-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harvey  Plimpton → Harvey Plimpton Construction; 2000-10-01 to 2016-04-05; source msha-controller-operator-history
- **operator_operates_mine:** Plimpton Excavating LLC → Extec Plant; 2016-04-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Harvey M  Plimpton Jr et al → Extec Plant; 2016-04-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harvey M  Plimpton Jr et al → Plimpton Excavating LLC; 2016-04-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harvey M  Plimpton et al → Plimpton Excavating LLC; 2016-04-06 to current/open; source msha-controller-operator-history