In Skyrim I have a quest to retrieve a mammoth tusk to help someone set up as a merchant. Of course, mammoths are generally being shepherded by giants. I do want to kill a giant at some stage but my character isn't quite ready for that yet. Is there any way to obtain a mammoth tusk without taking on a giant?
An easy place to find several mammoth tusks is in the Halted Stream Camp. You get a miscellaneous objective from Ahmren in Whiterun to retrieve his family sword, which may be located in the cave at the camp. In the same area as the sword, there is a shelf with 5-6 Mammoth Tusks just laying there, ripe for the taking. It's slightly North-Northwest from Whiterun's main gate. The symbol on the map looks like two sticks forming an X.
The probably easiest place to find the Mammoth Tusk is right outside Whiterun, at the Khajiit camp next to the stables or in Dawnstar.
Their caravan moves frequently, so you might have to wait for them to reappear, if they happen to be "on the move".
Ri'saad the merchant who sits in front of his tent has one.
Also don't forget to find the Transmutation book in Halted Stream Camp if your going there, its a useful spell to have around for making easy money.
You don't always have to fight giants to kill a mammoth, sometimes you can find one separated from the pack in the wilds, just roam around a bit, or buy a tusk from a merchant, or find one yet again in the wilds.
If you want something tuned a bit more to exploration, there's a few dead mammoths in the swamps to the northwest of the continent, a bit off the beaten path to Riften. I'm not sure if their spawn location is constant, but on the characters I've run through there, I've always found at least one with a tusk.
Go to Jorrvaskr (where the Companions are) in Whiterun. Go in the front door and make a right. Go up the steps and make another right before the staircase going down. The railing preventing you from falling down the stairs leading to the lower level is on your left and there is a chest to your right. Open the chest and there should be a mammoth tusk in there. If you join the Companions you can take it for free.