I stumped, what type of rock is this?

[Boxtopp]

Found this while looking for arrow heads. its about 6" long, fairly hard and heavy. Haven't seen anything like it in my area. At first i thought i was
man made Indian etc,. At closer look it looks natural to me? Please help me with this.

 

[Jhaddad8]

Maybe a columnar piece of basalt, where did you find it

 

[bevo]

basalt is my answer too.

 

[Boxtopp]

Maybe a columnar piece of basalt, where did you find it

Found Lower lake Ca. maybe it was brought here by Indians?

Thanks guys for responding and posting. Makes sense a type of basalt.