These look like UTM coordinates, though it's hard to know exactly which coordinate system was used. Perhaps have a look at the California State Plane Coordinate System - Fresno is in Zone 4.
If not, try looking at the Projected EPSG coordinate systems for California.
EDIT: I've confirmed that it is likely the California State Plane Zone 4 on this calculator. It's important to note that the X,Y units are in feet. If I plug in the X,Y coordinates, and choose California State Plane Zone 4 (0404) the results are what you have for lat/long.
Calculated Values - based on Degrees Lat Long to seven decimal places.
Position Type State Plane - California Zone 4
Degrees Lat Long 36.7448838°, -119.7915918°
Degrees Minutes 36°44.69303', -119°47.49551'
Degrees Minutes Seconds 36°44'41.5816", -119°47'29.7306"
State Plane X Y (Meters) 0404 1929309.220mE 656919.398mN
X Y (US Survey Feet) 0404 6329742.000ftUSE 2155243.059ftUSN
X Y (International Feet) 0404 6329754.660ftE 2155247.370ftN
UTM 11S 250759mE 4070206mN
UTM centimeter 11S 250759.50mE 4070206.23mN
Grid North -1.7°