# Relationship history for MSHA mine 1700692

Current hierarchy: **Cory J  Mitchell → P & K Sand & Gravel Inc → HEATH 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:** P & K Sand & Gravel Inc → HEATH QUARRY; 2001-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** C Bruce  Plummer et al → HEATH QUARRY; 2001-02-01 to 2026-06-23; source msha-controller-operator-history
- **controller_controls_operator:** C Bruce  Plummer et al → P & K Sand & Gravel Inc; 2001-02-01 to 2026-06-23; source msha-controller-operator-history
- **controller_controls_mine:** Cory J  Mitchell et al → HEATH QUARRY; 2026-06-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cory J  Mitchell et al → P & K Sand & Gravel Inc; 2026-06-24 to current/open; source msha-controller-operator-history