Ohio Rev. Code § 315.30
Previous to taking depositions as provided by section 315.29 of the Revised Code, at least twenty days' notice shall be given to the owner, his agent or attorney, if known, who has adjoining lands. If such owner, agent, or attorney is not known, or resides out of this state, the applicant shall give notice of his intention to take depositions at a certain time and place, by advertisement for six consecutive weeks, in a public newspaper published in the county where the land lies. The last insertion of such notice shall be twenty days previous to the time of taking such depositions. In the notice a description of the adjoining lands shall be given. Evidence of the notice shall be furnished the engineer prior to his taking any deposition. With his proceedings, which shall be in writing, the engineer shall return the original notices with the evidence of their having been served, and a copy of the advertisement with evidence of publication. Such advertisement and evidence of publication shall be recorded with the survey and depositions.
R.C. §315.30