Please see below for verbiage that can be put on OSU letterhead that insures a landowner for hosting an OSU program. Note that the letter should be signed before the program date. This can be used for any landowner. Municipalities should have their own insurance, what you see below is more geared for private homeowners and landowners.
Thank you for permitting participants in the Ohio State University Extension [Name] program to access your property for purposes of conducting a nature walk on [date(s)]. Should you know of any condition on your property that may be hazardous or that you wish the [Name] program to avoid, please let me know prior to [date of program]. In consideration for granting such access, you are hereby named as an additional insured on the Ohio State University’s program of insurance for purposes of this activity. You may access evidence of our insurance information by going to http://u.osu.edu/treasurer/files/2014/09/The-Ohio-State-University_GL-Ce....
We appreciate your support of the Ohio State University Extension program.