P Diddy and Bette Midler have become the latest celebrities to back an online campaign to raise money so Native American tribes can purchase land they consider sacred.
The fundraising effort aims to buy nearly 2,000 acres (800 hectares) of pristine prairie grass in the Black Hills of South Dakota.
Three days after the campaign began, P Diddy tweeted "Help save the Sioux Nation! Click here" and linked to the website.
Midler also lent her voice, tweeting: "Incredible story re the Sioux Sacred Grounds. Donate what you can." Around \$6,000 (£3,775) flowed in immediately after P Diddy's tweet.
The campaign will run until November 30, by which time the tribes of the Great Sioux Nation will need to have raised \$9m (£5.7m) in order to purchase the land.
The tribes have already got \$7m (£4.4m) for the 1,942 acres (786 hectares), which they call Pe' Sla or Old Baldy.
There are Sioux tribes in the Dakotas, Minnesota, Montana, Nebraska and Canada, and Pe' Sla is important to their creation story.
Tribal members have long held ceremonies there, and when the land was put up for sale they feared it would be developed because of its proximity to Mount Rushmore.
Landowners Leonard and Margaret Reynolds cancelled a public auction of the property earlier this year after tribal members expressed outrage.
The pair then accepted the tribes' offer to purchase the land for \$9m - provided they have the money on time.
P Diddy and Midler join actor Ezra Miller and hip-hop producer Sol Guy in showing their support for the cause.
Miller, who appears in The Perks Of Being A Wallflower, flew to South Dakota last month to film a nine-minute documentary-style video about the land that is being used as part of the online campaign.
He said the three days he spent in South Dakota learning about the land and the Lakota tribes was life-altering.
"From the moment I arrived to the moment I departed, I was struck repeatedly by an unshakable sensation that this land truly carried something unspeakably important," Miller said.
He said the fact that the Lakota tribes have done Sundance ceremonies on the land for thousands of years is a "magical reality" and America has erased too much of the land's true history.