# Relationship history for MSHA mine 4701177

Current hierarchy: **Bonnie L Sperberg → L. J. Sperberg Construction, Inc. → S & O Pit**

- 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:** Sperberg & Ohrmundt Inc → S & O Pit; 1950-01-01 to 1984-07-18; source msha-controller-operator-history
- **controller_controls_mine:** Emery  Ohrmundt → S & O Pit; 1950-01-01 to 1984-07-18; source msha-controller-operator-history
- **controller_controls_operator:** Emery  Ohrmundt → Sperberg & Ohrmundt Inc; 1950-01-01 to 1984-07-18; source msha-controller-operator-history
- **operator_operates_mine:** L J Sperberg Construction Inc → S & O Pit; 1984-07-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lawrence J  Sperberg → S & O Pit; 1984-07-19 to 2022-08-07; source msha-controller-operator-history
- **controller_controls_operator:** Lawrence J  Sperberg → L J Sperberg Construction Inc; 1984-07-19 to 2022-08-07; source msha-controller-operator-history
- **controller_controls_mine:** Bonnie L Sperberg → S & O Pit; 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