Do I need to support this 4″x 12″ Girder spanning 10′ 6″?

I live in the lower level of a one-story over daylight basement home built in 1972.

I am planning a remodel of the lower level and have a existing interior wall that I thought was non-bearing and could be removed easily, but now understand that there is a 4″x4″ post supporting a girder over-head.

The distance to the outside wall is 10′ 6″ and the girder is a Douglas Fir 4″x 12″.  I believe there are floor joints 2″x 10″x 10′  12″ on center resting in the Girder.

I want to remove the wall that ran under the girder to the outside wall (10’6″), but I’m concerned that the 10’6″ span is too wide for the 4″x 12″ girder.

Thanks for any comments.

Denis