# Relationship history for MSHA mine 1700720

Current hierarchy: **Lynn  Lakeman → VAUGHN THIBODEAU & SONS INC → Portable Plant**

- 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:** Vaughn  Thibodeau et al → Portable Plant; 1993-07-01 to 2007-12-10; source msha-controller-operator-history
- **operator_operates_mine:** VAUGHN THIBODEAU & SONS INC → Portable Plant; 2002-04-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vaughn  Thibodeau et al → VAUGHN THIBODEAU & SONS INC; 2002-04-15 to 2007-12-10; source msha-controller-operator-history
- **controller_controls_mine:** Lynn  Lakeman → Portable Plant; 2007-12-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lynn  Lakeman → VAUGHN THIBODEAU & SONS INC; 2007-12-11 to current/open; source msha-controller-operator-history