# Relationship history for MSHA mine 2601655

Current hierarchy: **Andreas  Steckenborn; Kelly  Malcolm → Borealis Mining Company, LLC → Borealis 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

- **controller_controls_mine:** Houston Oil & Minerals Corp → Borealis Mine; 1950-01-01 to 1981-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Tenneco Inc → Borealis Mine; 1979-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Houston International Minerals Corp → Borealis Mine; 1980-06-01 to 1981-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Houston Oil & Minerals Corp → Houston International Minerals Corp; 1980-06-01 to 1981-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Tenneco Minerals Company → Borealis Mine; 1981-05-01 to 1986-11-18; source msha-controller-operator-history
- **controller_controls_operator:** Tenneco Inc → Tenneco Minerals Company; 1981-05-01 to 1986-11-18; source msha-controller-operator-history
- **operator_operates_mine:** Echo Bay Minerals Company → Borealis Mine; 1986-11-19 to 2003-08-14; source msha-controller-operator-history
- **controller_controls_mine:** Echo Bay Mines Ltd → Borealis Mine; 1986-11-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Echo Bay Mines Ltd → Echo Bay Minerals Company; 1986-11-19 to 2003-08-14; source msha-controller-operator-history
- **operator_operates_mine:** Borealis Mining Company → Borealis Mine; 2003-08-15 to 2013-01-29; source msha-controller-operator-history
- **controller_controls_mine:** Gryphon Gold Corporation → Borealis Mine; 2003-08-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gryphon Gold Corporation → Borealis Mining Company; 2003-08-15 to 2013-01-29; source msha-controller-operator-history
- **operator_operates_mine:** Borealis Mining Company, LLC → Borealis Mine; 2013-01-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Waterton Global Value L P et al → Borealis Mine; 2013-01-30 to 2023-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Waterton Global Value L P et al → Borealis Mining Company, LLC; 2013-01-30 to 2023-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Gryphon Gold Corporation et al → Borealis Mining Company, LLC; 2013-01-30 to 2023-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Kelly  Malcolm et al → Borealis Mine; 2023-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kelly  Malcolm et al → Borealis Mining Company, LLC; 2023-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Andreas  Steckenborn et al → Borealis Mining Company, LLC; 2023-05-01 to current/open; source msha-controller-operator-history