# Relationship history for MSHA mine 2700470

Current hierarchy: **Norman  Brown → Pitcherville Sand and Gravel Inc. → New Ipswich Pit**

- 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:** Norman  Brown → New Ipswich Pit; 1996-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Pitcherville Sand and Gravel Inc. → New Ipswich Pit; 2013-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Norman  Brown → Pitcherville Sand and Gravel Inc.; 2013-03-20 to current/open; source msha-controller-operator-history