Some more cool stuff - the first item is TerreSculptor, it's a free terrain editor http://www.demenzunmedia.com/home/support/ the second item can be used with it.
To get terrain maps https://earthexplorer.usgs.gov/ you have to sign up for it, but it's free, you set points on any part of the map and it will let you download a terrain map for it.
After selecting the area that you want to grab for your terrain
You have to click on the "datasets" button and it gives you a list of download options, if you want to use it for TerreSculptor the dataset that you select will be under "Digital Elevation" ---> SRTM --> "SRTM void filled" ---> Click on the results button
After clicking on the "results" button it gives you a list of different files to download, click the download button for the ones that say 1-ARC and
download the one that says "BIL 1 Arc-second"
Open TerreSculptor and if your just starting the tool up there should be a welcome screen with an "import terrain" button
If you don't see it, go to "file" ---> "import terrain"
Then select the folder that it's in, make sure you change the file type to BIL
then you should see this screen
You should see a really detailed map now
if you want to see colors you can click on the "material" button on the right side and you will get
When done, there are well over 25 different file types you can export to by clicking on "file" on the top left and clicking "export" at least one of them should be compatible with leadwerks.
There are tons of tweaks you can make to the terrain, including changing the altitude, it's amazing all the options to choose from for a free terrain editor/creation tool.