# Relationship history for MSHA mine 4702901

Current hierarchy: **Bonnie L Sperberg → L J Sperberg Construction, Inc. → WASHING 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:** Lawrence J  Sperberg → WASHING PLANT; 1984-07-19 to 2022-08-07; source msha-controller-operator-history
- **operator_operates_mine:** L J Sperberg Construction, Inc. → WASHING PLANT; 1990-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lawrence J  Sperberg → L J Sperberg Construction, Inc.; 1990-04-01 to 2022-08-07; source msha-controller-operator-history
- **controller_controls_mine:** Bonnie L Sperberg → WASHING PLANT; 2022-08-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bonnie L Sperberg → L J Sperberg Construction, Inc.; 2022-08-08 to current/open; source msha-controller-operator-history