# Relationship history for MSHA mine 2902158

Current hierarchy: **Conner  Bjustrom → Red Hill Lava Products, Inc. → Portable Screener #1**

- 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:** Hecla Mining Company → Portable Screener #1; 1987-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mwca Inc → Portable Screener #1; 1996-06-01 to 2000-06-05; source msha-controller-operator-history
- **controller_controls_operator:** Hecla Mining Company → Mwca Inc; 1996-06-01 to 2000-06-05; source msha-controller-operator-history
- **operator_operates_mine:** Colorado Lava Inc → Portable Screener #1; 2000-06-06 to 2016-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Dan  Marion et al → Portable Screener #1; 2000-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dan  Marion et al → Colorado Lava Inc; 2000-06-06 to 2016-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Ronald D  Bjustrom et al → Colorado Lava Inc; 2000-06-06 to 2016-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Conner  Bjustrom → Portable Screener #1; 2016-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Red Hill Lava Products, Inc. → Portable Screener #1; 2016-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Conner  Bjustrom → Red Hill Lava Products, Inc.; 2016-08-01 to current/open; source msha-controller-operator-history