diff --git a/snowexsql/data.py b/snowexsql/data.py
index 636fe37..cd31745 100644
--- a/snowexsql/data.py
+++ b/snowexsql/data.py
@@ -46,7 +46,7 @@ class SingleLocationData(SnowData):
     northing = Column(Float)
     easting = Column(Float)
     elevation = Column(Float)
-    utm_zone = Column(String(10))
+    utm_zone = Column(Integer)
     geom = Column(Geometry("POINT"))
     time = Column(Time(timezone=True))
     site_id = Column(String(50))