I found the reference, Hardee is discussing the troops that he left in Arkansas and lists them as:

seven companies cavalry of Borlands Regiment and four companies infantry of McCarvers' and one independent company of infantry under Captain Roberts.

He goes on to say:

It is proper to add that I ordered the company under Captain Roberts to join me here, but it has not done so, nor do I know that it has let Pocahontas.

The War of the Rebellion: A Compilation of the Official Records of the Union And Confederate Armies. Series 1, Volume 3, page 236.

If this is indeed the Clark County Artillery, then appears that they either lost their guns or never had guns and were almost converted to infantry.