Reno, NV, June 29, 2007. Photographers concerned that microstock photography sites are undermining the value of their work have a new ally in their efforts to sell royalty-free images online. Meet SierraStock.com. SierraStock.com is the newest community stock photography site on the net, opening to the public on Thanksgiving 2006. This June, the site passed the 10,000 image mark and is nearing 200 contributors.