Is this the right idea for large terrain?

[anonymous_user_8a2ac0a9]

I’m working on incorporating real elevation data to create a terrain for my game. Here are the steps that I took:

1. Downloaded USGS DEM data in 1 arcsecond intervals for the area I wish to model
2. I loaded the data file into Terrescultor which can read the data file format and turn the height data into a heightmap
3. The resulting heightmap is 3212 x 3212. Each data point is 30 meters apart which works out to almost 96km for the whole map (3212 x 30 meters = 96360 meters)
4. Since this is too large for each landscape, I have to cut it down of course. Going by the landscape size recommendations, I chose 505px as the size I would create my map so I sliced my heightmap into 505px square tiles
5. I imported the cropped heightmap. Here is what I had:
   
6. Now all that was left before importing was to set the correct scale. Since each data point is 30 meters apart, I set X and Y to 3000.

Here is my result:

So what does everybody think? Was this the correct way to properly scale the map to fit the data? And does it even look like the heightmap? I’ve been staring at it for so long I’m not sure anymore. Also, I’m not sure how to adjust the Z scale for height. How can I figure out what the lowest and highest terrain height are without “driving” around the whole map so that I can adjust the scale? After importing the data into excel, I know that the minimum height for that particular area should be 64.79 meters and the maximum height should be 151.98 meters.