NBM Dive Site Resource
Mahnomen Mine Lake I
Crosby / Ironton, Minnesota, United States
A flooded Cuyuna iron-ore mine lake with established shore dive sites including WOMBAD Point, underwater trees, walls and railroad tracks.
Save this dive site to your free member profile.
Quarry Picture Placeholder
Aquatic life at this dive site
What divers may encounter
Three reviewed connections are featured here. Sightings vary by season, conditions, and chance, so they are never guaranteed.
Aquatic life research in progress
NBM is reviewing a likely local species for this position.
Aquatic life research in progress
NBM is reviewing a likely local species for this position.
Aquatic life research in progress
NBM is reviewing a likely local species for this position.
Site media
Photographs
Three views rotate from the published gallery on each visit.
Contributor media
Dive videos
Three featured video positions are reserved on every profile.Recent field observations
Diver-reported temperatures
Automatically checked observations from dives during the past 14 days. Three reports are visible at a time; scroll for more.A report that passes the automatic checks will appear here with the dive date, diver’s display name, and temperatures at each depth.
Reports are automatically checked for plausible dates, depths, and temperatures. They are observations, not forecasts; confirm conditions before diving.
Why divers know this place
Highlights
Flooded iron-mine topography, walls, roadbeds, submerged forests and site-specific placed attractions.
Quarry-only module
Quarry layout and services
This section appears only for quarries and mines, with the practical details divers need for entries, training areas, submerged features, surface support, and current operations.
- Current operating status
- Best practical access is generally during the ice-free season; verify roads and ice conditions.
- Submerged attractions
- Flooded iron-mine topography, walls, roadbeds, submerged forests and site-specific placed attractions.
- Onsite dive services
- Facilities vary by pit; arrive self-sufficient unless a current local operator confirms support.
- Surface facilities
- Facilities vary by pit; arrive self-sufficient unless a current local operator confirms support.
Before you arrive
Access notes
Use only legal state-recreation-area entries and a current local map. Extreme depth lies beyond recreational limits.
Plan within your training
Conditions and hazards
Extreme depth, cold water, multiple thermoclines, narcosis, regulator free-flow, silt, entanglement, submerged trees and limited emergency access.
At the site
Facilities and support
Facilities vary by pit; arrive self-sufficient unless a current local operator confirms support.
Independent resource notice
This record is a starting point for independent verification. Access, closures, moorings, weather, currents, depth, visibility, operator availability, and site conditions can change without notice. Confirm current information with the responsible operator, property owner, managing authority, or another qualified local source before planning or attempting a dive.