# Relationship history for MSHA mine 2700308

Current hierarchy: **Smith Dean A → Dean A Smith & Son → ROCKY RIDGE**

- 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:** Dean A Smith & Son → ROCKY RIDGE; 1996-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Smith Dean A → ROCKY RIDGE; 1996-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smith Dean A → Dean A Smith & Son; 1996-07-01 to current/open; source msha-controller-operator-history