# Relationship history for MSHA mine 1601531

Current hierarchy: **James J  Denman → Hard Rock Sand & Gravel → Hard Rock Sand & Gravel IV**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** James J  Denman → Hard Rock Sand & Gravel IV; 2002-06-11 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hard Rock Sand & Gravel → Hard Rock Sand & Gravel IV; 2013-07-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James J  Denman → Hard Rock Sand & Gravel; 2013-07-09 to current/open; source msha-controller-operator-history