Fir Mountain is located in the Southern Catskills and is a member of the 35 peaks over 3,500ft ranking 25th among them. Fir is a true bushwack that offers no views, but does have a canister at the summit. Despite the name, Fir does not have dense balsam fir forests; expect typical Catskills mixed hardwoods. Fir is one of the easier bushwhacks and is often done in conjunction with Big Indian since access is off the same trail and there isn't much elevation loss between the two. Fir is a good example of the bushwhack philosophy that says "go off the trail and keep going UP." and there isn't much elevation loss between the two.
Getting ThereDepends which trailhead your using but its 2.5 hours form NYC and 1hr 40 minutes from Albany.
There are a number of different routes that can be taken to get to the summit of Fir Mountain. But, all of them require a bushwack to get to the summit. Some routes run over marked DEC trails at the beginning of the hike. Others are bushwacks from the beginning. There are pros and cons to each direction depending upon the time of year, and the experience you are looking for. The nice part of this hike is the easy climb to the summit. The hike is moderate in ability. There are numerous stream crossings on the shown route. During high water periods, they may not be crossable or safe.
Route #1 - Hike from Biscuit Brook DEC Parking Lot - Straight Route- It is fairly easy hike, and moderate in ability. It does have some stream crossings that can only be crossed during normal water heights. During high water marks it can be very dangerous.This is the most common route used by most hikers 7.8miles
RT.Route #2 - Hike from Biscuit Brook DEC Parking Lot - Follow Ridge Line- This route has a very easy incline, but is longer than Route #1. It also has more bushwacking. Some people might take Route #1 to the top of the mountain, and follow Route #2 to return back to their car.
Route #3 - Hike from Slide Mountain DEC Parking Lot- This route goes over three mountains instead of one. It is more remote then the other routes. The beginning of the route requires that you climb up a steeper incline to get to the top of the ridge line. This is probably the least used route.
Route #4 - Hike from Big Indian Mountain- This route requires that you climb Big Indian Mountain first, and then hike over to Fir Mountain. It will add a couple miles to the hike. The col in between the two mountains is known for deep winter snow drifts, so keep this in mind if you hike this route in the Winter. Most people start at the Seagar parking area, or do a loop from the Biscuit Brook parking lot.
Route #5 - Hike from Burnham Hill Road off Rt 47- This route follows some old roads up the mountain, that come out near the col of Big Indian Mountain and Fir Mountain. This is only if you keep to the left as you take the old roads up the mountain.
Red TapeNo camping over 3,500 feet.
When to ClimbLike all of Catskills year round but be careful in highwater periods.
Below links are helpful and I lifted most the info here from these two places.