# Relationship history for MSHA mine 0202224

Current hierarchy: **Ashland Inc → Tanner Construction → Portable Crusher 20-195**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Tanner Companies → Portable Crusher 20-195; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tanner Companies → Portable Crusher 20-195; 1984-08-01 to 1987-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Tanner Companies → Tanner Companies; 1984-08-01 to 1987-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Tanner Construction → Portable Crusher 20-195; 1987-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ashland Inc → Portable Crusher 20-195; 1987-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc → Tanner Construction; 1987-09-01 to current/open; source msha-controller-operator-history