# Relationship history for MSHA mine 2600615

Current hierarchy: **Moreland William → Blackhawk → Blackhawk**

- 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:** Richfield Resources Inc → Blackhawk; 1950-01-01 to 1982-05-18; source msha-controller-operator-history
- **controller_controls_mine:** Griblin Frank → Blackhawk; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Griblin Frank → Richfield Resources Inc; 1950-01-01 to 1982-05-18; source msha-controller-operator-history
- **controller_controls_mine:** Morris William W → Blackhawk; 1982-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Minerals Unlimited Inc → Blackhawk; 1982-05-19 to 1982-12-01; source msha-controller-operator-history
- **controller_controls_operator:** Morris William W → Minerals Unlimited Inc; 1982-05-19 to 1982-12-01; source msha-controller-operator-history
- **operator_operates_mine:** Tseng Mining Company → Blackhawk; 1982-12-02 to 1984-12-05; source msha-controller-operator-history
- **controller_controls_mine:** Brown James R & Henry Hiel → Blackhawk; 1982-12-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brown James R & Henry Hiel → Tseng Mining Company; 1982-12-02 to 1984-12-05; source msha-controller-operator-history
- **controller_controls_mine:** Shelton Les → Blackhawk; 1984-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Moreland William → Blackhawk; 1984-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Keeler Production Company → Blackhawk; 1984-12-06 to 1988-07-27; source msha-controller-operator-history
- **controller_controls_operator:** Shelton Les → Keeler Production Company; 1984-12-06 to 1988-07-27; source msha-controller-operator-history
- **operator_operates_mine:** Blackhawk → Blackhawk; 1988-07-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Moreland William → Blackhawk; 1988-07-28 to current/open; source msha-controller-operator-history