Costco is planning an expansion of its stores in California with two new stores set to open soon. The big box retailer known for its bulk items and $1.50 hot dog will be opening a brand new store in North Visalia in the San Joaquin Valley on May 21 and will replace an existing store in Fresno. A Costco standalone gas station , the first of its kind, is also set to open later this year in Mission Viejo. There are also reports that the chain is interested in opening another store in Riverside County’s Menifee. As the company reported strong Q2 earnings in March with sales and income up, they’re spreading across the United States. CEO Ron Vachris announced during the call that the company aims to open 30 or more warehouses annually over the next five to 10 years, with about half in the U.S. California has by far the most Costco warehouse locations of any state, with 135 locations at present. There are also reports that the chain is interested in opening another store in Riverside County’s Menifee.…