# Relationship history for MSHA mine 0404092

Current hierarchy: **C M Inc → Ams Inc Of Nevada → Pearl (1) Or (2) 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

- **operator_operates_mine:** American Borate Company → Pearl (1) Or (2) Mine; 1950-01-01 to 1979-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Roscorp Inc  et al → Pearl (1) Or (2) Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roscorp Inc  et al → American Borate Company; 1950-01-01 to 1979-12-31; source msha-controller-operator-history
- **controller_controls_operator:** American Borate Corp  et al → American Borate Company; 1950-01-01 to 1979-12-31; source msha-controller-operator-history
- **controller_controls_mine:** C M Inc → Pearl (1) Or (2) Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ams Inc Of Nevada → Pearl (1) Or (2) Mine; 1980-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** C M Inc → Ams Inc Of Nevada; 1980-01-01 to current/open; source msha-controller-operator-history