How can I attain a Court Letter of Administration to manage a property of a Decedent after forty seven (47) years?

Mother died intestate a widow with several children and owned forty seven point five (47.5) acre of land and a small house thereon. All children were grown at time of death of the decedent, and none lived on said land, also there were no bank account, bonds, only land with house. Property Tax has been maintained by Sibling, and the dilapidated house was demolished in year 2004. Land is undivided and is Located in Columbia County Arkansas. The Sibling has followed their deceased mother's verbal desire that the land remain undivided. No Heirs have lived on this property. It has grown into a timber forest and now a letter of Administration is needed to open a Bank account to deposit property income. Arkansas has a five year limit on Probate and Administrations with a couple exceptions I hope there is a workable solution for this family.