I guess it is. That link doesn't have the footnotes, but in the book, footnote #67 on p.122 says:

The incident described here by Joseph M. Bailey is known in the annals of northwestern Arkansas as the Peach Orchard Massacre or Harp Massacre. Taking place on September 15, 1864, it resulted in the deaths of James M. Cecil, Samuel R. Harp, and Benjamin Riggs, all members of the First Arkansas Infantry U.S. Johnston, "Pension/Service/Bounty Abstracts," 10-22; Johnston, "Peach Orchard," 11-17.