Star Trek Expanded Universe

Starbase 20 was a United Federation of Planets Starfleet facility active in the 23rd and 24th centuries.

It was located near the galactic barrier. (Orion Press: "To Weather a Storm")

Commodore Gerald Morris was the vice commander of the starbase in the 2260s. (Starship Farragut)

In the mid-2280s, Admiral X.W. Sumers was a Starfleet Intelligence flag officer at the starbase. (FASA RPG: Where Has All the Glory Gone?)