The U.S. Postal Service will unveil three new stamps on Friday honoring Lewis and Clark in simultaneous ceremonies in 11 cities, including Sioux City. Postal Service spokesman Richard Watkins says the 37-cent self-adhesive stamps commemorate the great American explorers on the bicentennial of the start of their expedition — May 14th, 1804. One stamp features Meriwether Lewis and William Clark on a high bluff, surveying the countryside — it’s available in a sheet of 20 stamps. The other two are individual portraits of Lewis and Clark. Watkins says ceremonies will be held at 11 A.M. (central) at locations important to the expedition, stretching from St. Louis all the way to the Pacific Ocean. Governor Vilsack will attend the Sioux City “First Day of Issue” event. Watkins says serious stamp collectors may consider investing less than ten dollars to get a great keepsake. The post office is issuing ten each of the two portrait stamps in a special 32-page “prestige book” called “Lewis and Clark: The Corps of Discovery, 1804-1806,” available for eight-dollars, 95-cents. Watkins says there’s also a commemorative souvenir envelope or cache that’ll be available Friday and for the following 30 days. The Friday “First Day of Issue” ceremony is being held at center court of Southern Hills Mall in Sioux City, which features large murals depicting the explorers. Another ceremony is planned for 11 AM Friday as well in Omaha on the Missouri riverfront. For more information, surf to “usps.com” or to “www.southernhillsmall.com”.