Oregon Conference of Seventh-day Adventists | Gladstone, OR, The Oregon Conference of Seventh-day Adventists represents over 130 churches and 32 K-12 schools in Oregon and southwest Washington. The conference headquarters, located in Gladstone, Oregon serves its constituency by providing ministry and logistical support to pastors, teachers and over 36,000 members. The Oregon Conference is part of the world-wide Seventh-day Adventist Church which has a ministry presence in 217 nations and includes over 20 million members.