The Tallahassee project in Colorado has 25.4 million tonnes grading 490 parts per million U3O8.
A circa 10,000m drill campaign is planned.
Okapi rebadged itself as a uranium play earlier this year, with the acquisition of assets in the US completed less than two months ago.
It also has lithium prospect in Western Australia, and last month claimed a major discovery gold discovery in New South Wales.
The stock is up about 200% over the past few months.
Okapi is estimated to have cash of about A$5 million.
Shares in Okapi were up 9% to 61c in morning trade, capitalising the company at $62 million.