If you plan on hunting Unit 15 with ATV's your best bet is to hunt the logged out areas on Unit15c, the Alaska Native owned private land was logged out (removal of beetle killed mature spruce trees) in the late 80's early 90's thus creating new growth and awesome moose habitat with many miles of logging spurs/trails with access off the main highway south of Soldotna in the Clam Gulch ( yep, the clamming hot spot) and Ninilchik area, contact the Ninilchik Native Association for info.... I have hunted the areas numerous times with 100% success rate for moose, there have been 70"+ bulls taken there, my best was 62"... there is a fee that the Assoc. charges for access, you get a key to the gate and can come and go 24/7 as you feel for the entire moose hunting season, (August 20th thru Sept. 20th)...... the only problem is... there is a closure on the use of motorized vehicles from Sept. 11-14 and Sept. 17-20, ( you can use atv's up to Sept. 10th, on Sept. 15th, 16th and 21st and on) so you must plan on getting in/out prior and after the closures... we would thoroughly scout the area out before the closures and set up our main camp within walking distance of our moose calling locations.. on the plus side of the motor vehicle restrictions, it keeps all the road hunters out of the area and gets really good for calling moose, and yes !!! the moose do respond to calling in the area, far more effective than plodding around in the brush and swamps !!
***note***
the regs. have changed for Unit15 for moose, you may only take bull moose with 50'' or wider or 4 brow tines or more on at least one side, you cannot take spike/fork bulls anymore and you cannot take 3 brow tine bulls unless they are 50'' or wider.
I have also heard it may be for residents only now, not certain of that rumor, contact the Alaska Dept. of Fish and Game for verification and info .....