Agarwal et al. developed a data structure that maintains the MST for a graph belonging to a minor closed family. It uses the idea of a "swap", calculating the amount by which the weight of the MST would increase if some edge in the tree was replaced by an edge outside the tree such that the circle induced by in the tree contains. Maintaining the tree is then equivalent to finding and swapping the next pair for which this quantity becomes negative. This data structure considers the dual view of the graph, and then divides based on Frederickson's restricted partitions to make this efficient. It results in a total run time if insertions or deletions are made, or if only weight changes are allowed. These deterministic bounds are slightly improved if randomization is allowed.