# Relationship history for MSHA mine 0503107

Current hierarchy: **Hecla Mining Company → Durita Development Corp → Durita-Naturita 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Colorado Macco → Durita-Naturita Operations; 1977-10-01 to 1978-04-17; source msha-controller-operator-history
- **controller_controls_mine:** Colorado Macco → Durita-Naturita Operations; 1977-10-01 to 1978-04-17; source msha-controller-operator-history
- **controller_controls_operator:** Colorado Macco → Colorado Macco; 1977-10-01 to 1978-04-17; source msha-controller-operator-history
- **operator_operates_mine:** Durita Development Corp → Durita-Naturita Operations; 1978-04-18 to 1984-07-25; source msha-controller-operator-history
- **controller_controls_mine:** Ranchers Exploration & Development Corp → Durita-Naturita Operations; 1978-04-18 to 1984-07-25; source msha-controller-operator-history
- **controller_controls_operator:** Ranchers Exploration & Development Corp → Durita Development Corp; 1978-04-18 to 1984-07-25; source msha-controller-operator-history
- **operator_operates_mine:** Durita Development Corp → Durita-Naturita Operations; 1984-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hecla Mining Company → Durita-Naturita Operations; 1984-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hecla Mining Company → Durita Development Corp; 1984-07-26 to current/open; source msha-controller-operator-history