# Relationship history for MSHA mine 4406235

Current hierarchy: **Donald L  Shaffer → Southampton Sand Company L C → SOUTHAMPTON SAND CO., L.C.**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Walter R  Bishop Jr → SOUTHAMPTON SAND CO., L.C.; 1980-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** W R Bishop Jr Inc → SOUTHAMPTON SAND CO., L.C.; 1985-07-01 to 1990-10-28; source msha-controller-operator-history
- **controller_controls_operator:** Walter R  Bishop Jr → W R Bishop Jr Inc; 1985-07-01 to 1990-10-28; source msha-controller-operator-history
- **operator_operates_mine:** Ivor Sand Company Inc → SOUTHAMPTON SAND CO., L.C.; 1990-10-29 to 1998-04-20; source msha-controller-operator-history
- **controller_controls_mine:** Henry  Layden → SOUTHAMPTON SAND CO., L.C.; 1990-10-29 to 1998-04-20; source msha-controller-operator-history
- **controller_controls_operator:** Henry  Layden → Ivor Sand Company Inc; 1990-10-29 to 1998-04-20; source msha-controller-operator-history
- **operator_operates_mine:** Southampton Sand Company L C → SOUTHAMPTON SAND CO., L.C.; 1998-04-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Donald L  Shaffer → SOUTHAMPTON SAND CO., L.C.; 1998-04-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donald L  Shaffer → Southampton Sand Company L C; 1998-04-21 to current/open; source msha-controller-operator-history