Find a map of Northern CA.
Using a compass, draw a circle 5 miles in diameter from Roseville.
Do the same, but then draw as circle 23 miles from Sacramento.
Finally, draw your last circle, 110 miles in diameter from Oakland.
The 3 cities are not in a straight line, but would form a rough triangle on a map.
For your information, when distances are calculated to or from a city, it is a convention to use City Hall as the measuring point.
From the information you've given I'd say the picnic area is in North Highlands, or Fair Oaks.