Fire Spotting.

Anyone here familiar with Aerial Firefighting?

I've found fires to be an ever-present fact of life flying here in
California. I've personally spotted at least two young, fast-moving
brush fires, one of which was during on my solo long cross country.
My instinct when I see these fires is always to tell someone,
especially if the fire appears particularly young (small). Is this
correct? I want to help, but I fear 'bugging people' about it.

The situation in particular which got me thinking, I took off from
Columbia and headed out for an overflight of Yosemite. As we flew up
the valley, we noticed a tiny but quickly growing brush fire about 20
miles East of half dome, way up in the park.

I could not reach either Center or Fresno Approach, so I decided to
jump back on Columbia's (A firefighting base) CTAF and call out for
any Firefighting aircraft. I got one of the bomber pilots on
frequency, relayed the fire position, and he said they hadn't heard of
that one and they were on their way to check it out.

It felt good to help... or he was being nice, I'm not sure.

So my question is, as a private pilot, should I feel a 'duty' to call
in forest fires? Is it actually helpful? If so, what are/is the
best frequencies and procedures to use?

Any insight would be appreciated.

-Scott