An Optical Survey of the Position Error Contours of Unidentified High-Energy Gamma-Ray Sources at Galactic Latitude |b| > 20°

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We present results from our optical survey of the position error contours (error boxes) of unidentified EGRET sources at mid-to-high Galactic latitude. It is our intention to search for potential blazars that may have been missed in the original identification process of the three EGRET Catalogs and supplementary publications. We have first searched the error contours of unidentified sources at |b| > 20° for flat-spectrum radio sources using the NASA/IPAC Extragalactic Database. For each such radio source found, we conducted optical searches for counterparts using the Palomar 60 inch (1.5 m) telescope and the University of Wyoming's 2.3 and 0.6 m telescopes. Many of the radio sources have plausible optical counterparts, and spectroscopy will be conducted at a later date to determine which of these sources are quasars or active galaxies. Results show that several sources are optically variable and/or have flat or inverted radio-to-millimeter spectra and are thus potential blazars.