The West Texas Weather Modification Association is a non-profit association of underground water districts in West Texas providing water production via cloud seeding. Staff includes a manager, meteorologist, a full time pilot as well as contract pilots. Cloud seeding in West Texas has been ongoing since 1995. Located at Mathis Field in San Angelo, the WTWMA utilizes single engine Piper Comanche aircraft for their operations. The WTWMA is part of a larger organization, the TWMA, where opportunities to work in South Texas and/or in the Trans-Pecos region will be likely as well.