# Relationship history for MSHA mine 4606135

Current hierarchy: **Shultz Emmitt → Gulf Coal Processing Corp → Prep Plant No 1**

- 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:** D & G Coal Processing Company → Prep Plant No 1; 1980-03-01 to 1981-10-13; source msha-controller-operator-history
- **controller_controls_mine:** Goldberg Robert L → Prep Plant No 1; 1980-03-01 to 1981-10-13; source msha-controller-operator-history
- **controller_controls_operator:** Goldberg Robert L → D & G Coal Processing Company; 1980-03-01 to 1981-10-13; source msha-controller-operator-history
- **operator_operates_mine:** Gulf Coal Processing Corp → Prep Plant No 1; 1981-10-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Shultz Emmitt → Prep Plant No 1; 1981-10-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shultz Emmitt → Gulf Coal Processing Corp; 1981-10-14 to current/open; source msha-controller-operator-history