The newer Magellan Topo (3D) uses the 30M Digital Elevation Model (DEM) from the USGS.
There is an elevation point every 30M as opposed to every 90M as before in the prior release. This allows for calculating a more accurate elevation. Unless I'm mistaken, it is not just interpolating, it is using a lot more data points to calculate contours. Wouldn't it be is less misleading than the lack of elevation contours?
So are you saying that the Garmin 24K National parks topo and 100K US topo have the same DEM?
Can't see anywhere that they specify the granularity of their mapping data.
The Garmin Topo misses a lot of saddles etc because it does not have the data needed.
The built in memory of almost all current Garmin outdoor units really limits their ability to cover much area with higher detail. 33.6MB covers TOPO for Colorado on Garmin, Lowrance takes 125MB (including GMUS & & street info). Don't have the information for Magellan before/after their change to finer grained DEM. However, comparing data sizes can be apples/oranges comparison based on data formatting.