# Relationship history for MSHA mine 1401792

Current hierarchy: **Sandra Lee Williams → Williams Diversified Materials, Inc. → Portable #4**

- 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:** Larry L  Bingham → Portable #4; 1950-01-01 to 2012-12-27; source msha-controller-operator-history
- **controller_controls_mine:** Sandra Lee Williams et al → Portable #4; 2012-12-28 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Williams Diversified Materials, Inc. → Portable #4; 2017-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sandra Lee Williams et al → Williams Diversified Materials, Inc.; 2017-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Larry L  Bingham → Williams Diversified Materials, Inc.; 2017-11-14 to 2012-12-27; source msha-controller-operator-history