One of the coins - an 1874 $20 double eagle - is scheduled to be auctioned at the Old San Francisco Mint on at 8:30 p.m. Tuesday.
Don Kagin, whose firm is handling the sale, says most of the remaining 1,400 coins will go on sale on Amazon.com and Kagins.com later in the evening.
The coins date from 1847 to 1894 and have been valued at $11 million.
The couple, whom Kagin declined to identify, found them last year buried under the shadow of a tree on their rural Northern California property.
Kagin says there have been numerous theories about the coins' origins, but none have panned out.