Tyhee Submits Revised Project Description Report for its wholly-owned Yellowknife Gold Project

For immediate release
Release: Series 9 Release 13
TSX Venture: TDC

– Mine Permitting Process To Proceed –

Vancouver, British Columbia – July 28, 2008 – Tyhee Development Corp. (TSX Venture: TDC) announces today it has submitted a revised Project Description Report for its wholly owned Yellowknife Gold Project to the Mackenzie Valley Land and Water Board (MVLWB). The submission envisions a combined open pit and underground mining operation delivering to a centrally-located mill located adjacent to the Ormsby Zone.“This report will allow Tyhee to continue to advance our principal asset, the wholly-owned Yellowknife Gold Project, through the environmental assessment process,” said David Webb, President and CEO of Tyhee Development Corp. “By continuing to focus on the potential of our existing claims, we expect to strengthen our position as the dominant property holder in the Yellowknife gold camp.”

This submission outlines the current operational parameters for the Yellowknife Gold Project and replaces the application submitted in March 2005. Since the project’s operational parameters have changed from those submitted in 2005, Tyhee NWT Corp was advised by both the MVLWB and the Mackenzie Valley Environmental Impact Review Board (MVEIRB) to submit a new application.

Today’s submission is in line with the expectations of both Boards which will enable the project to proceed through the environmental assessment process. It is expected that once the MVEIRB holds scoping sessions and issues terms of reference for the Developers Assessment Report (DAR), Tyhee could then be in a position to prepare the DAR for submission early in 2009.

About Tyhee Development Corp.

Tyhee Development Corp. is a gold exploration and development company currently focused on the historic Yellowknife Gold Camp, NWT, Canada. It is the largest property holder in the historic camp, and has the largest exploration and development program underway in the region. Its principal asset is the advanced-stage Yellowknife Gold Project, which consists of 6,625 hectares (15,481 acres) of mining leases located 90 km (56 miles) north of Yellowknife, NWT, Canada. A recently released Preliminary Assessment demonstrated positive economics at 3,000 tpd for seven years, producing 1.1 million ounces with additional potential to expand operations. Three additional gold properties have been acquired within the Yellowknife Gold Belt and further acquisitions are being considered.

NO REGULATORY AUTHORITY HAS APPROVED OR DISAPPROVED THE CONTENT OF THIS RELEASE. THE TSX VENTURE EXCHANGE DOES NOT ACCEPT RESPONSIBILITY FOR THE ADEQUACY OR ACCURACY OF THIS RELEASE.

Tyhee’s shares trade on the TSX Venture Exchange under the symbol “TDC”. For additional information, please visit the Company’s website, www.tyhee.com .

For further information please contact:

Tyhee Development Corp.
David Webb, President and CEO
Tel: 604-681-2877
toll free 1-866-681-2877
info@tyhee.com