On June 15, 2010, at 1533 mountain daylight time, a Schleicher Alexander GMBD ASH 26E glider, N455S, and a Schempp-Hirth Ventus 2CT glider, N514TW, were involved in a mid-air collision about 75 miles northeast of Parowan, Utah. Neither pilot was injured. Both pilots were the sole occupants of their respective gliders. The ASH 26E sustained substantial damage, and the Ventus 2CT sustained minor damage. Both pilots were operating under the provisions of 14 Code of Federal Regulations Part 91 in visual meteorological conditions. Both gliders departed Parowan, Utah (N455S at 1403, and N514TW at 1344), and Parowan was the planned final destination for both pilots. No flight plan had been filed. According to both pilots, they were competing in a glider competition task that required them to depart a point near Parowan, fly to a point about 90 miles northeast of Parowan, and then to return to Parowan for landing. Both pilots where flying back to Parowan after reaching the turnaround point when they entered the same thermal and began to climb. During their first full turn in the thermal, the left wing of the ASH 26E and the nose of the Ventus 2CT came in contact. The impact resulted in the separation of the outboard three feet of the wing of the ASH 26E, and denting of the lower nose area of the Ventus 2CT. The pilots of both gliders were able to return to Parowan, where they both completed uneventful landings. Both pilot's stated that they had not seen the other glider as they entered the thermal, and both pilot's stated that they realized that it was their responsibility to see and avoid any other gliders that were climbing in the same thermal.