So my local G&F placed a bunch of habitats in one of the lakes and published the GPS coordinates online.  I believed they used the UTM system.  

 

Forgive my ignorance, but I'm having a hard time figuring out how to enter them.  I understand you can change the type of coordinates your unit uses.  For example, it could be Degrees, degrees minutes second etc.  When I select UTM and try to enter these numbers it just doesn't seem to work out.  Any advice would be appreciate.

 

Northing: 3725761.104

Easting: 491376.808

Wow, I can't believe they are publishing points in UTM.  Personally I would not change my fish finder to use UTM.  I would convert the coordinates before entering them.  That way you will be using the same system as every other fisherman and every fishing map ever printed.  Just google "UTM converter" and you should find plenty of online converters to do this for you.  It's been a LONG time since I looked at UTM.  I know a UTM coordinate requires a zone number which you did not give with the point you provided.  They may state somewhere on the website that all of the points are in a certain zone.   It might also be possible to switch your Lowrance to UTM,  enter the points,  and then switch it back to geo coordinates and it would convert them for you.  Sorry but I'm not a Lowrance user so I can't help with that.

 

UPDATE:  I did some searching on the web and checked all of the UTM zones in the US with the coordinates you gave.  Zone 12 was the only one in water and is on Theodore Roosevelt Lake.  If this is your lake then your point is in zone 12 and might be written like this  12 N 491376.808 3725761.104