Topher Gaylord has resigned as president of Mountain Hardwear, the mountaineering brand owned by the Columbia Sportswear group. A dedicated ultra runner, Gaylord took the helm in 2010, after several years as an executive at The North Face and other parts of VF Corp. Scott Kerslake, the chief executive of Prana, the yoga and outdoor brand bought by Columbia Sportswear last year, has taken over as interim president at Mountain Hardwear, while remaining in charge at Prana. Mountain Hardwear's sales were off by 10 percent last year and they slid by another 23 percent in the first quarter of this year, but in May the company still predicted roughly stable sales for the brand in the full year.