With the development of nanotechnology, new applications have been created for separating and manipulating biomolecules using micro- or nano-fluidic devices. It is therefore essential to understand the underlying physics and transport properties of highly confined macromolecules. Such knowledge will not only be important for the development of polymer physics, but also could help the design and optimization in future applications. Here we experimentally study the relaxation dynamics of large DNA in thin gaps. The longest relaxation time is determined in one of two ways- either by monitoring the rotational motion of molecules at equilibrium or by following the relaxation of stretched DNA back to equilibrium. In addition, we measure the long-time diffusivity of the DNA at equilibrium. We compare our results to scalings predicted by blob theories. Of note is the fact that in blob theory the product of the diffusivity and relaxation time is proportional to the equilibrium size of the DNA – thus we can test both dynamical and static predictions of blob theory. For the case of a stretched DNA relaxing in a slit channel, we find new regimes that are absent when compared to relaxation of an unconfined polymer.