Have a fixed position div that needs to scroll if content overflows

I have actually two issues, but lets resolve the primary issue first as I believe the other is easier to address.

I have a fixed position div on the left side of the scroll for a menu. Right side is a standard div that scrolls properly. The issue is that when the browser view-port is too small to see the entire menu.. there is no way to get it to scroll that I can find (at least not with css). I've tried using different overflows in css, but nothing makes the div scroll. The div that contains the menu is set to min-height:100% and position:fixed.. both attributes I need to keep.

The div containing the menu is inside another wrapper div that is positioned absolutely and height set to 100%.

How can I get it to scroll vertically if the content is too tall for the div?

That leads me to the other issue, that i don't want a scroll bar to display.. but I think I may already have an answer to that (only it doesn't work yet because I can't get the div to scroll to begin with).

Any solutions? Perhaps javascript is needed? (of which i know little about)

JS Fiddle Example

and the relevant code that is causing the issue (since posting the whole thing in here is waaay too long):

.fixed-content {
    min-height:100%;
    position:fixed;
    overflow-y:scroll;
    overflow-x:hidden;
} 

Also tried adding height:100% as well just to see if that was an issue but it didn't work either... nor did a fixed height, such as 600px.

The problem with using height:100% is that it will be 100% of the page instead of 100% of the window (as you would probably expect it to be). This will cause the problem that you're seeing, because the non-fixed content is long enough to include the fixed content with 100% height without requiring a scroll bar. The browser doesn't know/care that you can't actually scroll that bar down to see it

You can use fixed to accomplish what you're trying to do.

.fixed-content {
    top: 0;
    bottom:0;
    position:fixed;
    overflow-y:scroll;
    overflow-x:hidden;
}

This fork of your fiddle shows my fix: http://jsfiddle.net/strider820/84AsW/1/

The solutions here didn't work for me as I'm styling react components.

What worked though for the sidebar was

.sidebar{
position: sticky;
top: 0;
}

Hope this helps someone.