The segment is a retelling of the famous roughest, toughest cowboy in the west, Pecos Bill and his trusty steed Widowmaker. Roy Rogers and the Sons of the Pioneers explain to two kids at their campsite why coyotes howl at night and end up retelling the story of Pecos Bill. The segment explains life of Pecos and how some of the West's famous landmarks and features have come to be, because of Pecos Bill.
The feature takes a turn when Pecos falls in love with Slue-Foot Sue. This makes Widowmaker feel abandoned and jealous of Sue for stealing his best friend. Bill and Sue plan on getting married but she insists on wearing a bussel on her backside made from metal and springs. She also wants to get married while riding Widowmaker which makes Widowmaker more angry than ever.
Sue expertly rides the violently bucking horse until the sympathetic bouncing in her bussle launches her off Widowmaker sky-high, with each bounce launching her higher and higher.
The town thought all was lost for Sue, but Pecos did not sweat it, for he (a the greatest champeen of the lasso) was going to effortlessly catch her with his trusty rope... but shockingly, he missed! No one who witnessed it could ever figure out how it happened, but the viewers can see that it was Widowmaker who purposely stepped on Pecos' rope preventing it from reaching Sue.
With Pecos unable to arrest her ascent, Sue kept going higher and higher until she finally landed on the moon, "and that's where she stayed".
The narrator then relates that Pecos left civilization and would howl at the moon every night, with his coyote brothers joining in sympathy; and that is the reason that to this very day, coyotes howl at the Moon that way.
The segment and the film end with Roy Rogers and the Pioneers reprising the song Blue Shadows On the Trail.
Pecos Bill has been edited for content in versions commonly seen on Disney television: all references (both visual and in song: "Pecos rolled a smoke and lit it") are removed and the segment referring to "painted indian" Native Americans was cut. The segments were restored for the DVD release.