# Relationship history for MSHA mine 4201546

Current hierarchy: **Harper Investments Inc → Harper Sand & Gravel Inc → PIT #6**

- 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:** Harper Investments Inc → PIT #6; 1978-03-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Harper Sand & Gravel Inc → PIT #6; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harper Investments Inc → Harper Sand & Gravel Inc; 1979-01-01 to current/open; source msha-controller-operator-history