# Relationship history for MSHA mine 2600614

Current hierarchy: **N R D Mining Ltd → National Resources Development Inc → Nevada Scheelite**

- 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:** Kennametal Inc → Nevada Scheelite; 1950-01-01 to 1979-01-11; source msha-controller-operator-history
- **controller_controls_mine:** Kennametal Inc → Nevada Scheelite; 1950-01-01 to 1979-01-11; source msha-controller-operator-history
- **controller_controls_operator:** Kennametal Inc → Kennametal Inc; 1950-01-01 to 1979-01-11; source msha-controller-operator-history
- **operator_operates_mine:** Westley Mines Limited → Nevada Scheelite; 1979-01-12 to 1979-11-07; source msha-controller-operator-history
- **controller_controls_mine:** Poliquin J Duane → Nevada Scheelite; 1979-01-12 to 1979-11-07; source msha-controller-operator-history
- **controller_controls_operator:** Poliquin J Duane → Westley Mines Limited; 1979-01-12 to 1979-11-07; source msha-controller-operator-history
- **operator_operates_mine:** National Resources Development Inc → Nevada Scheelite; 1979-11-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** N R D Mining Ltd → Nevada Scheelite; 1979-11-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** N R D Mining Ltd → National Resources Development Inc; 1979-11-08 to current/open; source msha-controller-operator-history