Are your maps oriented to grid north or true north?

MyTopo maps are UTM projected, so they are always oriented to (UTM) grid north.

However, when creating a custom map, in Step 4: Personalize, you can turn on latitude/longitude Full Grid Lines which will run true north.  UTM gridlines (which also can be enabled) will run grid north. NAD83/WGS84 and NAD27 Datums are both supported.

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