# Relationship history for MSHA mine 2800549

Current hierarchy: **John L  Silvi; Laurence J  Silvi II → Sahara Sand of Port Norris → Sahara Sand of Port Norris**

- 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

- **operator_operates_mine:** Ricci Bros. Sand Co., Inc. → Sahara Sand of Port Norris; 1950-01-01 to 2019-12-22; source msha-controller-operator-history
- **controller_controls_mine:** Samuel J  Ricci Sr → Sahara Sand of Port Norris; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Samuel J  Ricci Sr → Ricci Bros. Sand Co., Inc.; 1950-01-01 to 2019-12-22; source msha-controller-operator-history
- **operator_operates_mine:** Sahara Sand of Port Norris → Sahara Sand of Port Norris; 2019-12-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John L  Silvi  Et Al → Sahara Sand of Port Norris; 2019-12-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John L  Silvi  Et Al → Sahara Sand of Port Norris; 2019-12-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Laurence J  Silvi II  Et Al → Sahara Sand of Port Norris; 2019-12-23 to current/open; source msha-controller-operator-history