# Relationship history for MSHA mine 3401153

Current hierarchy: **Bill W  Smith → Bill Smith Sand & Gravel Inc → Plant 612**

- 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:** Bill W  Smith → Plant 612; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Two State Crusher Inc → Plant 612; 1978-03-09 to 1981-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Moser H M → Plant 612; 1978-03-09 to 1981-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Moser H M → Two State Crusher Inc; 1978-03-09 to 1981-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Bill Smith Sand & Gravel Inc → Plant 612; 1981-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bill W  Smith → Bill Smith Sand & Gravel Inc; 1981-09-01 to current/open; source msha-controller-operator-history