# Relationship history for MSHA mine 2900181

Current hierarchy: **Eagle Materials Inc → American Gypsum Company LLC → White Mesa**

- 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:** Pomeroy Inc → White Mesa; 1950-01-01 to 1985-02-24; source msha-controller-operator-history
- **controller_controls_mine:** Angus W Pomeroy → White Mesa; 1950-01-01 to 1985-02-24; source msha-controller-operator-history
- **controller_controls_operator:** Angus W Pomeroy → Pomeroy Inc; 1950-01-01 to 1985-02-24; source msha-controller-operator-history
- **operator_operates_mine:** American Gypsum Company LLC → White Mesa; 1985-02-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Eagle Materials Inc → White Mesa; 1985-02-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eagle Materials Inc → American Gypsum Company LLC; 1985-02-25 to current/open; source msha-controller-operator-history