Was heading n on hwy 83 from mccook,ne to a fedex facility near north platte, ne. blue and sunny skies,a few clouds, mid 40s. maybe 25 miles out, i happened to look at the sky (as usual) and saw what i at first assumed was a plane gaining altitude. but the angle was wrong. almost 45 degrees. too steep for most planes and besides there are no airports in the area that could have such a craft. the nearest jet-powered craft capable airport was about 90 miles east. realizing too that the shape was not that of a plane. it was stick-like and was white with light. also it moved fast. as i watched, it went behind and into a small narrow cloud and did not come out. the sky west of the cloud which was the crafts direction of travel was was completely clear and blue. the craft did not come out the other side which it should have done in a few short seconds. not there anymore. that was when it dawned on me that i was probably seeing a "ufo". on its trajectory, and at its speed it absolutely should have come out and continued on its course. it did not. it was not seen by me again. imagine a shape that is 1/8"x 5/8". it was of course at some distance but that will give you the idea. so thar tis.