Yes, there's a dipstick attached to the filler cap on the reservoir. Or rather, there's supposed to be - it's somewhat easy to break off.

In general the fluid level is supposed to be perhaps 3 inches below the top with the car fully unloaded. In practice it seems to work fine with the level quite a bit lower. Just be aware that loading up the car will transfer that fluid into the rear suspension (the accumulators, really) and you don't ever want the bottle to run dry.

- JimY