# Relationship history for MSHA mine 4703347

Current hierarchy: **William  Buell; Neil F  Plourde → Rivard Stone, Inc. → Portable**

- 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:** Rivard Stone, Inc. → Portable; 2003-04-09 to 2015-06-05; source msha-controller-operator-history
- **controller_controls_mine:** Michael L  Rivard et al → Portable; 2003-04-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael L  Rivard et al → Rivard Stone, Inc.; 2003-04-09 to 2015-06-05; source msha-controller-operator-history
- **controller_controls_operator:** Deborah K  Rivard et al → Rivard Stone, Inc.; 2003-04-09 to 2015-06-05; source msha-controller-operator-history
- **operator_operates_mine:** Rivard Stone, Inc. → Portable; 2015-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Neil F  Plourde et al → Portable; 2015-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Neil F  Plourde et al → Rivard Stone, Inc.; 2015-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William  Buell et al → Rivard Stone, Inc.; 2015-06-06 to current/open; source msha-controller-operator-history