This post helped me figure all this out.

I need to access a USB hard drive in NTFS on FreeBSD. In order to mount NTFS partitions, FreeBSD uses ntfs-3g FUSE module.

First, make sure the fuse kernel module is loaded. This can be done adhoc with kldload fuse. But to have it loaded at boot time, add the following line in /boot/loader.conf:

Then, install fusefs-ntfs package:

pkg install fusefs-ntfs

Now the OS supports NTFS, you can plugin the device. Use dmesg to figure out the device ID (d0):

Use gpart to show its partitions:

> ~ gpart show /dev/da0
=>        63  3907024833  da0  MBR  (1.8T)
          63        1985       - free -  (993K)
        2048  3907022848    1  ntfs  (1.8T)

You can also find the device node for the partition under /dev:

Now we are ready to mount it:

ntfs-3g /dev/da0s1 /mnt -o ro

-o ro makes sure it's mounted read-only. You can remove it to mount it read-write.

Note that I tried to use mount hoping there is a consolidated command for mounting different kinds of file systems. But it wasn't successful:

Also note that usually mounting a partition can only be done by root, or using sudo, which result in the mounted path is owned by root:wheel. However you can mount the partition as a specified user and group using uid and gid options.

First, find out the user and group IDs of the preferred user:

# id john
uid=1001(john) gid=1001(john) groups=1001(john),0(wheel)

Now run following command to mount:

Now /mnt is owned by john:john.