I suspect they’re talking of the road to/from Pine Log

There is a Pine Log Creek running from a few miles SE from Resaca, South East to Pine Log P. O. which is located about 13 miles East of Adairsville
See OR Atlas Plate 88-2

…………

Report of Major David A. Briggs, Second Indiana Cavalry.*
HEADQUARTERS SECOND INDIANA CAVALRY,
17, 1864.

SIR: I have the honor to report following result of the expedition under my command to Jasper:

With detachments of the First Wisconsin, Fourth Indiana, and Second Indiana Cavalry, numbering 235 men, I rpcoeeded on the old Tennessee road fourteen miles, thence on the Pine Log road three miles to the Pine Log and Cassville road. Here I learned that a force of rebels, consisting of one brigade, under command of General Hannon, and two pieces of artillery, had moved out from Jasper oin the Adairsville road in the direction of Calhoun and Resaca; also that one brigade had gone in the direction of the rolling-mills on the Etowah River.

War of the Rebellion: Serial 109 Page 0106 SW. VA., KY., TENN., MISS., ALA., W. FLA., &. N. GA. Chapter LXIV.

…….

IN THE FIELD,

May 18, 1864-12.25 p.m.

Major-General SCHOFIELD,
Commanding Twenty-third Army Corps:

I have the honor to state that I am at the cross-roads where you directed me to proceed. It is eight miles from here to Adairsville, seven to Pine Log Post-Office, and eleven to Cassville. Some rebel cavalry are reported four miles below me at junction of Cassville and road leading into old Federal road. I have sent down to see whether they are in force or not. If I am to march toward Cassville I desire at least a section of my battery to accompany me. You can sent it back over the road. This staff officer comes to me at this point. If you are through with regiment that went in your advance, be kind enough to send it as an escort. Any orders you may have to communicate can be brought back to me by my staff officer.

I am, general, very respectfully, your obedient servant,

E. M. McCOOK,
Colonel, Commanding

War of the Rebellion: Serial 075 Page 0241 Chapter L. CORRESPONDENCE, ETC. - UNION.