# Relationship history for MSHA mine 4605415

Current hierarchy: **Basham Calvin R → Technology Production Inc → #2 Surface**

- 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:** Chapman Henry → #2 Surface; 1974-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** California Fuel Company → #2 Surface; 1977-01-01 to 1983-06-14; source msha-controller-operator-history
- **controller_controls_operator:** Chapman Henry → California Fuel Company; 1977-01-01 to 1983-06-14; source msha-controller-operator-history
- **controller_controls_mine:** Basham Calvin R Et Al → #2 Surface; 1982-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Technology Production Inc → #2 Surface; 1983-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Basham Calvin R Et Al → Technology Production Inc; 1983-06-15 to current/open; source msha-controller-operator-history