I don't think a "blind luck" check can reach the 95,040 range (widest part of the Grand Canyon).
Remember that the average person can only ever reach (about) a jump check of 10, which is a running start (of 20 feet or more).
From a standing position, the average person will only be able to reach about 5 feet.
Likewise, an average person (with a running start) can reach about a 3 foot high jump, or a 1 foot high jump with no start.
Halflings actually have a racial bonus to Jump of +2.
It is up to you, as the DM, to determine when a Jump is more or less difficult, and when it is impossible at all. Watching Olympic long jumpers in action can show you about the height necessary to achieve great distances, rarely above about fifteen feet of clearance.
Edit: Remember, a lot of things in D&D don't make perfect sense. Also, any check above about 20 is impossible for the average JoeSchmoe, and in the realms of heroes and villains who specialize in that sort of thing.