It depends on what grounds the trailer is there in the first place:1) If the owner of the trailer is a tenant of yours--that is, he rents the land--then you may evict him when his tenancy is over. That means that if he rents it pursuant to a written lease, when the term of the lease is up or, if it's an oral lease, on 30 days notice. You have to go through the courts to evict him, but you are not required to renew his tenancy perpetually; while you can't evict him during the term of a lease, as long as he honors his obligations, you may evict him when the lease is up. (If you inherited the land, you inherited it subject to any leases that were in place at the time.)2) If he was just a "guest" of the previous owner, you can treat him as a month to month tenant (oral lease) effectively and give him notice terminating his tenancy, then evict if necessary.3) If, however, he has some more enduring or permanent right to be there--for example, a lease with many years left to run; an easement to use that stretch of land; or a life estate to have his mobile home there--you may be stuck with him; you can't evict him in violation of some right to remain, even if that right was given by the previous owner, siince you inherit land subject to not just leases, but also life estates, easements, and the like.Therefore, it is critical that you ascertain the basis for his residency; that will help you understand what exactly your rights are.