Clearing title in Yuma County Arizona

I am currently in the process of purchasing a vacant parcel of land located in Yuma County, Arizona. The most recent recorded deed for this property dates back to 1970 when it was transferred to a married couple. Subsequently, the property was placed in a trust for the couples children. However, both of the children have since passed away, and now the grandson of the original owners is seeking to sell the property. Given this situation, I am looking for an attorney familiar with clearing title in Arizona and any recommendations you may have.