Here in Massachusetts, if a person uses recreational land, free of charge, which is open to the public and then sustains an injury while on the land, the owners of that recreational land are most likely immune from suit unless the person can prove that the accident happened due to the wilful, wanton or reckless conduct of the landowner. G.L. c. 32, s. 17C applies in such cases and protects the landowner unless the injured person can prove that: a) the landowner knowingly and intentionally disregarded an unreasonable risk; and b) that risk entails a high degree of probability that substantial harm could result to the claimant- that is the standard for proving wilful, wanton or reckless conduct and it is a very difficult standard to satisfy.
This means that if you are hiking in parks or even fishing, biking, motocrossing, 4-wheeling, etc., on land to which the public has access, and no fee or charge was imposed, you will have to prove wilful, wanton or reckless conduct before you can recover against the landowner, if injured. Please note, however, that if the landowner charges a fee to allow you on the land, the injured person only has to prove simple negligence to recover.
When navigating your way through injury claims, it is obviously best to get the advice of an experienced lawyer.