Washington State Ferries is close to signing a lease extension with Pierce County for the Steilacoom II.

The extension will ensure car ferry service through the summer of 2010 when a permanent ferry for the Port Townsend to Keystone ferry route rolls out of the shipyard.

The original lease between the two entities expired Tuesday, but they agreed to a short-term lease extension that goes until the end of September. That provides enough time for both sides to work out details to the longer lease.

Michael Esher, administrator for Pierce County Airports and Ferries, said his staff wasn’t able to get a proposed lease to the ferry system until about a week before the deadline. That didn’t provide enough time for ferry officials to review the lease, so both sides agreed to the six-week extension.

“I don’t anticipate any major concerns,” Esher said.

Pierce County leased the Steilacoom II to Washington State Ferries in early 2008 after the ferry system pulled the four Steel Electric ferries from service due to safety concerns. To date the 54-car ferry is the only vehicle ferry officials have found capable of navigating through the difficult entry into Keystone Harbor. The ferry system payed Pierce County $850,000 to lease the Steilacoom II from Jan. 18, 2008 to Aug. 18, 2009.

Leasing out the Steilacoom II leaves Pierce County with one ferry to serve its ferry route. The Christine Anderson is about the same size but older.

Esher said the Pierce County ferry route has been fortunate this summer because there haven’t been any service interruptions, Last year, however, there were several such occasions. When Pierce County loses the Christine Anderson, the state has 24 hours to provide a replacement vessel.