The beaches around Yachats — particularly the gravel bars at the river mouth and the low-tide zones below the basalt shelves — are among the better agate-hunting spots on the central Oregon coast. The local agates are small, milky-to-translucent, and sometimes colour-banded: the product of silica-rich volcanic processes in the basalt. They show best when wet, which is why beachcombers work after winter storms when fresh material has been tumbled onto the beach by heavy surf.
The best conditions are the morning after a high-energy winter storm, at low tide, on the gravel sections rather than the sandy beach. You are looking for stones that transmit light when held up — the translucency distinguishes agates from ordinary grey beach pebbles. No permit is required and there are no quantity limits for personal collection. It is a meditative activity and entirely free; many regular Yachats visitors do it every morning as a matter of habit.