Tyhee Development Corp. Reports Start-up of Summer Drill Program at Clan Lake, Yellowknife Gold Project, NWT, Canada

VANCOUVER, May 31 /PRNewswire-FirstCall/ -- Tyhee Development Corp. (TSX Venture, TDC) (the "Company") is pleased to announce the re-start of its 2010 diamond drill program at Clan Lake, Yellowknife Gold Project. This program will see a further 4,000 metres +/- of diamond drilling on the Clan Lake Main Zone.

Tyhee's spring drill program included 485 metres in 16 drillholes on the Ormsby Zone and 7,140 metres in 21 drillholes on the Clan Lake Main Zone. Reporting for this program will continue over the next few weeks as 6 diamond drillholes remain to be reported.

Tyhee has filed a response to the Mackenzie Valley Environmental Impact Board, stating that it anticipates submitting its Developers Assessment Report in the forth quarter of this year. This delay is due to several factors, primarily a change in primary consultants as well as limited access to the remaining consultants during the summer field season.

Tyhee also announces the retirement of Mr. Roger G. Sylvestre from the management and the board of Tyhee. Roger was a founder of the company and has spent the past 18 years building Tyhee. As a former diamond drill company owner/operator Roger has worked more than 50 years in the mining industry. He used his knowledge to successfully manage the logistics and execution of our exploration and development programs. He will remain available to the company for consulting services on an ad hoc basis. The board and management of Tyhee would like to extend a heartfelt thanks to Roger for the many years of service to the company.

Tyhee Development Corp. is a gold exploration and development company working to start gold production in the historic Yellowknife Gold Camp, NWT, Canada. It is the largest property holder in this camp and has the largest exploration and development program underway in the region. Its principal asset, the Yellowknife Gold Project includes the Nicholas Lake, Ormsby, Bruce, Goodwin Lake, and Clan Lake Gold Zones. All are located on mineral claims and mining leases 50 to 90 km north of Yellowknife, NWT and are expected to feed a single milling operation. (Note: only Nicholas Lake and Ormsby Zones are being included for permitting purposes).

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Tyhee Development Corp.

CONTACT: Tyhee Development Corp. David Webb, President and CEO, Tel:
[phone], [e-mail]; Envoy Strategic Partners, Jay Bedard, Tel:
[phone], [e-mail]