((NUFORC Note: We suspect the witness was observing contrails, generated by high-altitude aircraft. PD))Object appeared as a contrail,did not dissapate,cast a shadow as tho solid,travelled intact to the southI was east bound on I-94,toward Madison.At approximately 15:00 I noticed three chem-contrails at aproximately 30,000 feet.The first was layed in a NW to SE trajectory for at least 200 miles.The second was the same length.However it was layed in a true S to N stream.The third chem-contrail was layed more than 50 miles away from the previous two.This chem-contrail appeared much more rapidly than the others.I believe this was not a chem-contrail.There are several reasons for this.1) As the first two C-Trails dissipated and became more cloud like the third did not change in opacity or refraction.2) The third C-Trail seemed to move at an extremely slow rate of speed toward the southern horizon WHILE REMAINING INTACT.3) The third C-Trail cast a huge shadow that left a shaft of dark blue from the darkened underside to the ground that was as the tho the C-Trail was a solid object.This shadow was cast from above Toma south past Madison moving with the object south,but also spreading to the East as the Sun approached the western horizon.I would estimate the size of the shadow to be at least 200 miles long and 100 miles wide at its widest spread, before twilight.I noticed one individual at a rest area,MP 115 on I90 that was observing the phenomena with a small telescope from a rifle.I am a long haul trucker and I have seen a number of unexplainable situations and phenomena over the years.I have seen fire balls that explode in silence within a few hundred feet of the ground.I watched six perfectly formed cloud rings that were hundreds of miles across travel across the pre-dawn sky from south to north in Michigan, disappearing into Canada as the Sun broke the eastern horizon.I sat at a rest area south of Black River Falls,Wis,watching a Red Tailed Hawk circle in a perfect blue sky.As I was watching the Hawk an irregular shaped part of the sky changed through the colors of the rainbow,moving from east to west at a high rate of speed.Perhaps these are naturally occurring events that I am not familiar with but,I wonder if we are not being observed by someone or something that has learned how to camouflage their activities.There is a hidden air base at Camp McCoy and Camp Douglas Wis. that is protected from view by a small range of mountains that run paralel to I 90/94.I have seen Fighters and B-52s shoot from behind those mountains in the pre-dawn hours when traffic and other activity seems to be slow.