# Relationship history for MSHA mine 0404716

Current hierarchy: **Portola Minerals Company → Blue Mountain Minerals → BLUE MOUNTAIN MINERALS**

- 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:** Blue Mountain Quarries → BLUE MOUNTAIN MINERALS; 1984-07-01 to 1987-12-21; source msha-controller-operator-history
- **controller_controls_mine:** Daniel E  Cripe  et al → BLUE MOUNTAIN MINERALS; 1984-07-01 to 1987-12-21; source msha-controller-operator-history
- **controller_controls_operator:** Daniel E  Cripe  et al → Blue Mountain Quarries; 1984-07-01 to 1987-12-21; source msha-controller-operator-history
- **operator_operates_mine:** Blue Mountain Minerals → BLUE MOUNTAIN MINERALS; 1987-12-22 to 1994-08-09; source msha-controller-operator-history
- **controller_controls_mine:** Bechtel & Sequoia Ventures Inc → BLUE MOUNTAIN MINERALS; 1987-12-22 to 1994-08-09; source msha-controller-operator-history
- **controller_controls_operator:** Bechtel & Sequoia Ventures Inc → Blue Mountain Minerals; 1987-12-22 to 1994-08-09; source msha-controller-operator-history
- **operator_operates_mine:** Blue Mountain Minerals → BLUE MOUNTAIN MINERALS; 1994-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Portola Minerals Company → BLUE MOUNTAIN MINERALS; 1994-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Portola Minerals Company → Blue Mountain Minerals; 1994-08-10 to current/open; source msha-controller-operator-history