# Relationship history for MSHA mine 0202464

Current hierarchy: **Mariah Interntl Inc-Guildmark Ind Inc & Flagstaff → Mariah Guildmark Joint Venture → Sheep Hill Pilot Plant Operations**

- 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:** Mariah Guildmark Joint Venture → Sheep Hill Pilot Plant Operations; 1988-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mariah Interntl Inc-Guildmark Ind Inc & Flagstaff → Sheep Hill Pilot Plant Operations; 1988-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mariah Interntl Inc-Guildmark Ind Inc & Flagstaff → Mariah Guildmark Joint Venture; 1988-11-01 to current/open; source msha-controller-operator-history