# Relationship history for MSHA mine 0404612

Current hierarchy: **Bennett Norman L → Vulcan Mining & Development Company → Cassill Mine**

- 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:** Ted  Youngquist → Cassill Mine; 1981-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Youngquist Mining Company → Cassill Mine; 1982-10-01 to 1984-08-06; source msha-controller-operator-history
- **controller_controls_operator:** Ted  Youngquist → Youngquist Mining Company; 1982-10-01 to 1984-08-06; source msha-controller-operator-history
- **controller_controls_mine:** Como Don C → Cassill Mine; 1983-08-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** International Recovery Inc → Cassill Mine; 1984-08-07 to 1987-05-12; source msha-controller-operator-history
- **controller_controls_operator:** Como Don C → International Recovery Inc; 1984-08-07 to 1987-05-12; source msha-controller-operator-history
- **operator_operates_mine:** Vulcan Mining & Development Company → Cassill Mine; 1987-05-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bennett Norman L → Cassill Mine; 1987-05-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bennett Norman L → Vulcan Mining & Development Company; 1987-05-13 to current/open; source msha-controller-operator-history