Utah Code § 40-1-1: Lode claims -- Size and shape -- Discovery necessary.

A lode mining claim, whether located by one or more persons, may equal, but shall not exceed, 1,500 feet in length along the vein or lode and may extend 300 feet on each side of the middle of the vein at the surface, except where adverse rights render a lesser width necessary. The end lines of each claim must be parallel. No location of a mining claim shall be made until the discovery of the vein or lode within the limits of the claim located.