# Relationship history for MSHA mine 2301840

Current hierarchy: **BMC Enterprises Inc → BMC Sand LLC → BMC Sand Eureka Plant**

- 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:** Robert  Smerker → BMC Sand Eureka Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Arnold Ready Mix Corp → BMC Sand Eureka Plant; 1981-04-01 to 2000-02-14; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Smerker → Arnold Ready Mix Corp; 1981-04-01 to 2000-02-14; source msha-controller-operator-history
- **operator_operates_mine:** Eureka Materials → BMC Sand Eureka Plant; 2000-02-15 to 2023-04-10; source msha-controller-operator-history
- **controller_controls_mine:** William  Kopp  et al → BMC Sand Eureka Plant; 2000-02-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William  Kopp  et al → Eureka Materials; 2000-02-15 to 2023-04-10; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Kopp  et al → Eureka Materials; 2000-02-15 to 2023-04-10; source msha-controller-operator-history
- **controller_controls_mine:** BMC Enterprises Inc → BMC Sand Eureka Plant; 2016-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** BMC Sand LLC → BMC Sand Eureka Plant; 2023-04-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** BMC Enterprises Inc → BMC Sand LLC; 2023-04-11 to current/open; source msha-controller-operator-history