How do you guys determine if land is public or private. For example if there is a small bridge over a river and I want to trap under there how do I even figure out who to ask. How do I figure out if it’s public or private. If I can learn it’s private I assume I could eventually find the land owner but I was just wondering.

Easiest for me and property lines.....OnX app on your phone. It'll get ya close.
Not cheap though. And definitely not survey accurate, but surprisingly close.

town office have maps of land owners in nh they are tax maps i do not know about ohio also call your fish and game ask to talk to the warden in your area he maybe able to help

My understanding would be that the bridge has a ROW just like the road would have, if thats the case the ROW belongs to the county or state.

Right of way access varies by state. Most of the south the right of ways are off limits and under the assumed control of the adjacent landowner.
In some areas they are public but to trap require permission of adjacent landowners.
As for actual ownership your county tax assessor should have a "bound book" mapping out land plats or deeds showing property lines and ownership. In many cases this is now available online either through your county gis/engineering or a private entity such as the mentioned OnX app.

Go to the county courthouse and buy a plat book, sometimes the public library will have a cope but it’s often in the reference material and can not be checked out, it will show property lines and current owners and often have their listed address in the back

Here road right away and water that will float a 12 foot canoe is classified as public (for the most part) as well as marsh land or lake shore that touches a public road way is considered accessible to the public as long as it’s accessed from the roadway for its entire serface area or length

There are exceptions and I know of some hunters and trappers that have been ticketed for not know them so I always consider it a good idea to get permission if at all possible to access it

I know each state is different but that’s how it is here

Those plat books are a good resource if your trapping in and around non public lands just to make sure your not unintentionally trespassing

Mason,
As other have said, I use On-x. It’s kinda spendy, but I found it on sale on an outdoor website occasionally. Pm me if you want the site I got it from

Plat book can get one at the court house usually

Land glide app

VT state has a atlas map on the natural resources website which gives you the approximate land boundry lines,tax map ID number and owner info. I have called the local town road commissioner for information also. I had a warden giving me trouble once until I produced the written road commissioners permission to trap letter from my truck. I was warned about this warden by another trapper so I was ready and I had problems with him before and made him call his superior and I was correct and he was wrong the phone call was on speaker and after the call the warden left without saying a word. He no longer Is in my area. Not shure where he ended up after his wife drew a moose permit and he was the second shooter on the permit and they both shot a moose . Two moose shot because they were too far apart from each other Illegally way of hunting but of course he didn't get the same fine you or I would have!!!

Ohio has plat maps showing property owners, I used them extensively when I lived in Ohio.

Like warrior said, the ROW situation may differ by state. In Kansas, almost all (maybe all, but just covering the bases) county road ROW's are EASEMENTS. The land is still owned by the adjacent landowner, so permission has to be obtained from the landowner on that particular half of the road/bridge. Here, the state buys the ROW needed for state roads from the landowner so the state owns those, but the county generally does not buy the land. Kansas law allows the county to have an easement (basically on section lines) for the road. At least this is my understanding of the situation here.

Lots of what ifs here. Each state has their own laws. Some roads are owned by the state some have right of ways (the right to use but not owned). Some land boundaries go to the high water mark some include the stream bed. Bottom line the land and stream bed could be owned by the state or an adjacent land owner. If the stream is considered navigable a whole set of different rules will apply.

I’ll just ask in the Ohio state forum.

or PM catch22.someone from ohio could tell ya.

NJ has a website with interactive maps of public lands. Sort of hard to translate the aerial photos to the real world sometimes. I've called the NJDEP before and asked them to email me maps of specific WMA's or State Parks.

I ended up using google maps to overlay those maps in the areas around where I live. It was technically challenging but I can now open google maps on my cell phone, zoom into where I am and see exactly where the boundary lines are.

Yep, plat books.
They are available in each county, generally in the $30-40 range, a bit more in the larger counties. Usually sold in the county clerk's office and the university extension office

Give your local game warden a call. He /she will know.

I use a app called Huntstand.