Many quasi-circular depressions (QCDs) revealed in the Mars Orbiter Laser Altimeter data set have no obvious structural representation in visible images of Mars. It has been suggested that these QCDs are surface representations of buried impact craters, and on the basis of this assumption, cumulative count versus diameter plots of QCDs in the northern lowlands have been constructed to date the buried lowland floor. If the QCDs are, in fact, buried impact craters, their surface relief should scale directly with their diameter; this relationship holds true for 115 QCDs with diameters ranging from 7 to 100 km within roughly 1500 km of the center of the Utopia Basin. The coefficient of determination (R2) of the relationship more closely approaches 1 when QCDs in zones of comparable cover thickness are evaluated. The surface relief versus diameter relationship of 55 randomly selected pseudo-QCDs was also determined; their poor correlation indicates that the direct relationship of surface relief to diameter of actual QCDs is due to differential compaction of a cover material over buried impact craters and is not just a random effect of QCD diameter. The slope of the trend of the QCDs' surface relief versus diameter, when divided into zones of comparable cover thickness, can be used to determine which zones have thicker or thinner cover.