Ask the Experts / Need Help with Opening Downloaded Parks

Whenever I download a park from the site I can not get it to open. I've downloaded many parks and none of them i can open on my roller tycoon game. What should I do to see if i can open any of the parks I download. Thanks for your help.
I have RCT2

Most parks are for RCT1...not RCT2.

Parks with the ".sc4" extension are for RCT1, and parks with the extension ".sc6" are for RCT2.

Why still use RCT1?

Most parkmakers are partial to the way of "hacking", which includes stacking scenery, merging two different track types, etc.
More parks are coming out for RCT2, but especially since the release of Wacky Worlds, nobody is feeling the need to switch to a dying, and glorified expansion pack, dubbed "RCT2."

It's sv4 and sv6. The sc4 and sc6 files are scenarios....

You may also need to install the Drexler Patch but don't install that until you've installed the official patch too.