# Relationship history for MSHA mine 2500947

Current hierarchy: **Jim  Palser → Beltline Sand & Gravel Inc → Kolberg 271**

- 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:** Yamada Kay → Kolberg 271; 1978-08-17 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Quality Gravel Company → Kolberg 271; 1979-01-01 to 1983-10-30; source msha-controller-operator-history
- **controller_controls_operator:** Yamada Kay → Quality Gravel Company; 1979-01-01 to 1983-10-30; source msha-controller-operator-history
- **operator_operates_mine:** Beltline Sand & Gravel Inc → Kolberg 271; 1983-10-31 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jim  Palser → Kolberg 271; 1983-10-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jim  Palser → Beltline Sand & Gravel Inc; 1983-10-31 to current/open; source msha-controller-operator-history