Urbavore’s Dilemma: Christie Isenberg aims to till the asphalt jungle

At the corner of 15th and California streets, the busy heart of downtown, an earth mover scrapes away at a newly exposed 8,000-square-foot stretch of dirt bounded by chain-link fencing. Surrounded by the 16th Street Mall, the Denver Pavilions, the Hyatt Regency Denver and the Denver Dry Goods Company Building,…