  An Impulsive Heating Multiple Strand (IHMS) Model is able to reproduce the
observational characteristics of EUV (~ 1 MK) active region loops. This model
implies that some of the loops must reach temperatures where X-ray filters are
sensitive (> 2.5 MK) before they cool to EUV temperatures. Hence, some bright
EUV loops must be preceded by bright X-ray loops. Previous analysis of X-ray
and EUV active region observations, however, have concluded that EUV loops are
not preceded by X-ray loops. In this paper, we examine two active regions
observed in both X-ray and EUV filters and analyze the evolution of five loops
over several hours. These loops first appear bright in the X-ray images and
later appear bright in the EUV images. The delay between the appearance of the
loops in the X-ray and EUV filters is as little as 1 hour and as much as 3
hours. All five loops appear as single ``monolithic'' structures in the X-ray
images, but are resolved into many smaller structures in the (higher
resolution) EUV images. The positions of the loops appear to shift during
cooling implying that the magnetic field is changing as the loops evolve. There
is no correlation between the brightness of the loop in the X-ray and EUV
filters meaning a bright X-ray loop does not necessarily cool to a bright EUV
loop and vice versa. The progression of the loops from X-ray images to EUV
images and the observed substructure is qualitatively consistent with the IMHS
model.
