Checking OED for their earliest cite I was surprised to see it was 1898 in connection with the Australian gold rush.

1893 G. TREGARTHEN Austral. Commw. 158 The *gold-rush had introduced many unruly spirits.

Of course, one can’t read too much into that but is there no evidence that earlier gold rushes (California, 1848, springs to mind, of course) were called such at the time?

Well, I found an 1870 cite at “Making of America”
Title: The New world compared with the Old,
Author:  Townsend, George Alfred, 1841-1914.
Publication Info: Hartford, Conn.,, New York,: S. M. Betts & company,, J. D. Dennison; [etc., etc.], 1870.
But surprisingly it’s also about the Australian gold rush:

The progress of Melbourne is that of San Francisco. “ Some of the New South Welsh,” says Mr. Dilke, an author, “ shutting their eyes to the facts connected with the gold rush, assert so loudly that the Victorians are the refuse of California, or ‘Yankee scum,’ that when I first landed in Melbourne, I expected to find street-cars, revolvers, big hotels, and fire-clubs, euchre, caucuses, and mixed drinks.

Found an 1884 reference to the California one.
Title: Etc.
Publication Info: Overland monthly and Out West magazine. / Volume: 3, Issue: 1, Jan 1884, pp. 103-107

...the idea brought up by the word “California” was of leisurely and patriarchal Spanish sway, vast herds and feudal domains, a dreamy, pastoral life in a country of exhaustless fertility and peaceful simplicity; the still more familiar romance of the gold rush;…

At MOA Cornell I found this:
Life in the Cannibal Islands, by J. C. Bates: pp. 529-543 in:
Title:  Scribners monthly, an illustrated magazine for the people. / Volume 1, Issue 5
Publisher:  Scribner and son.  Publication Date:  March 1871
City:  New York

which has this in reference to New Zealand (the writer appears to have participated in the California gold rush, but is currently talking about Dunedin):

One morning the waiter pushed aside
several dirty socks to make room for my
plate. This was the last straw. If the filthy
things had been removed from the table, I
might have stood it; but to have them by the
side of my plate was more than human nature
could stand—even while “roughing it” in the
first days of a new gold rush.

His ”a new gold rush” suggests that he’s thinking of the California event as the same sort of thing, but that still doesn’t tell us how long after 1849 the term came to be applied there.

Via Google Books:

“Pictures of Gold Rush California.”
Absaraka (Ab-sa-ra-ka), Home of the Crows (1868), by Margaret Irvin Carrington, p. i (and apparently three other pages, though gottverdammte Snippet View won’t show the relevant text)

A GOLD RUSH [chapter title; refers to Australia]
The Boy in the Bush (1869), by Edward Howe, p. 213

“Give us a gold rush and we are made men.” [refers to Australia]
Narrative of a Voyage Round the World, (1872), by Edward Belcher and Richard Brinsley Hinds, p. 305

“It may be premised here, as a reason why so many families were on this occasion caught by the flood, that prior to the gold rush in 1867 there had been no settlers in this country...” [refers to Australia]
The Queen of the Colonies; Or, Queensland as I Knew it (1876), by E. Thorne, p. 110

This is extremely tantalizing: Letters Writen [sic] by Andrew T.W. Jack to His Wife, Julia Ann Wood-Jack, During His Travels to the California Gold-rush and Chile, South America, published 1851, but Google Books won’t even show a snippet view!

Those antipodean references are intriguing, coupled with the OED cite. I’d always assumed that the great California gold rush was called such at the time. If not, I wonder what the contemporary term was, or if indeed there was a predominant term.

Just seen your post, lh. Very interesting results, especially the 1851 book.

BTW was ‘49 the first great gold rush in the US?

Using Newspapercrchive--

_Marshall(IA) County Times_ 13 Oct 1858 is the earliest use I can find in US papers.  There is a NY Times cite from 1861, but their next one is 1875.  So, not common.

"Gold” and “rush” are linked here, though not as a “gold rush”:

The adventurers of the present day, incited by the lust of gold, rush on improvidently, and totally regardless of hazard, if they may only reach the golden Sierra of the West.

Google books 1850

Great find, Eliza!

Searching through the electronic archives of The Times (of London), it appears that “rush for gold” was the expression used at least in the middle decades of the century, to describe a run on the banks by nervous depositors wishing to exchange their notes for the greater assurance of metal, as in this letter from “An Irish Landlord” on Wednesday, December 17, 1834, pg. 5, col B

… in all times of political agitation there have been certain scoundrels ever ready to raise the cry of “Rush for gold!”

So perhaps this expression and its meaning hampered the use of “gold rush” to mean the flood of men to dig gold up, rather than the flood of men to take gold away from a bank ...

At any rate by the 1850s The Times was using “rush” alongside “gold” to mean something rather different, the rush of gold out of the diggings, as in this report from Thursday, April 08, 1852, pg. 8, col F

The Gold-Fields Of Victoria.
(from the Melbourne Argus of Dec 20)
On the 19th of last month we published a calculation of the estimated amount of gold which had then seen the light of day, derived from the various diggings of this colony … our desire to be rather below than above the market had led us to estimate the latter quantities far too low, and the rush of gold which has since been poured upon the market quite baffles all ordinary rules of calculation.

However, the first mention in The Times I can find for “gold rush” (still 35 years before the OED’s first cite) does not come until another dispatch from Australia, Monday, January 11, 1864, pg. 8, col B:

From our own correspondent, Melbourne, Nov 25 1863 ...

… The railway works, commenced so vigorously a few weeks ago at Echuca, on the Murray, have since suffered some check from the superior attractions of the Raywood new gold rush, which has sprung up in the neighbourhood and drawn away some of the navvies from their work.

which suggests that “gold rush” had become a common term by 1864 that did not need any explaining to Times readers.

It’s fascinating to me that the vast bulk of the early uses refer to Australia—I would never have guessed!