In 1947, because of increased post-war power demand and consumer desire for less expensive electricity, Sierra Pacific began negotiating for new supplies, including with the Bureau of Reclamation, which had excess capacity available from the recently completed Shasta Dam.

In 1954 the FPC issued an order upholding its decision not to reject the new rate and finding it to be not "unjust, unreasonable, unduly discriminatory, or preferential.

Mobile Gas held that the NGA did not authorize a unilateral contract change,[2] and that holding also applied to the FPA.

The Supreme Court in its companion case Mobile Gas found a similar result regarding contracts filed with the FPC involving electricity sales under the NGA.

Under this doctrine, an electricity or gas rate specified in a freely negotiated contract is presumed to be "just and reasonable" and thus acceptable under the FPA or NGA.

1 of Snohomish County (2008), the Supreme Court determined that the Mobile-Sierra doctrine also applied when the burden of the improvident contract was on the purchaser.