# Relationship history for MSHA mine 0401965

Current hierarchy: **Sharp Glen & Tom Dyke → Imperial Cement & Tom Dyke → La Posta Sand 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

- **operator_operates_mine:** Stevens Trucking Inc → La Posta Sand Plant; 1950-01-01 to 1989-04-10; source msha-controller-operator-history
- **controller_controls_mine:** Stevens C R → La Posta Sand Plant; 1950-01-01 to 1989-04-10; source msha-controller-operator-history
- **controller_controls_operator:** Stevens C R → Stevens Trucking Inc; 1950-01-01 to 1989-04-10; source msha-controller-operator-history
- **operator_operates_mine:** Imperial Cement & Tom Dyke → La Posta Sand Plant; 1989-04-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sharp Glen & Tom Dyke → La Posta Sand Plant; 1989-04-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sharp Glen & Tom Dyke → Imperial Cement & Tom Dyke; 1989-04-11 to current/open; source msha-controller-operator-history