A thermal reach enhanced geothermal wellbore has a plurality of fissures at a target location that distally extend into the formation and that are at least partially filled with a compacted high-thermal k material. The compacted high-thermal k material terminates on a proximal end of the fissure at the target location of the wellbore and is thermally coupled to a high-thermal conductivity grout or slurry through which heat is conducted to a working fluid that is contained in a closed loop working fluid conduit embedded in the grout or slurry.