Trust or Partnership? or something else

My understanding is we are going to an attorney who specializes in more problematic Estate Planning than our oil and gas attorney is contacting them, can personally do. The Texas plan is for the development of an LLC to place the Oil and Gas interests in. There’s 4 States involved; Texas, New Mexico, Oklahoma and Colorado where mineral interests are owned. Our Attorney is a Texas attorney so may not know Probate would be required in Oklahoma. So that may change “The Plan” of not having to go through Probate.