According to the Mars Direct plan, crews will open new territories on Mars every other year to exploration and settlement.  Eventually, one of these territories will be selected as the best possible location for the first permanent Mars base.  When that territory has been designated, all the crews will report to that chosen territory and continue to add habitats to that territory.  The transportation of the habitats can be conducted by attaching wheels to them so they can roll and connect to one another.  In essence, what is really happening is that the Mars base can be rapidly built up as an interconnected network of Mars Direct style habitats.

    The only problem that lies within this plan concerns the issue of how to house the population; however, this can be easily solved by developing large habitable structures separate from the interconnected network.  This will employ the same "live off the land" approach we employed to get the planet, as these structures can be assembled out of native materials.