I estimate that there are presently about 300 permanent residents of Trinidad, California.  I will explain why I believe this is so.  But I must add that this number is deceptively small because there are many more people who say they are from Trinidad but do not actually reside within the official City Limits.  So I will also describe Trinidad's postal ZIP code area, also called the Greater Trinidad Area, its neighborhoods and its population count.

In the 2000 Census (1), 311 people lived within the Trinidad City Limits.  In the previous 1990 Census (2), 362 people lived in Trinidad.  I think it is likely that still fewer people reside in Trinidad today.  New home building has been slow and the demography is changing.  The median age and income of Trinidad residents have gradually risen.  The proportion of older persons is increasing, and the proportion of young working families with children is decreasing.  Some homes that were permanent residences have become vacation residences.  All of these changes have been subtle and gradual, yet for the reasons I stated, I expect that in the 2010 Census, Trinidad will find it has even fewer permanent residents than it had in 2000.

The postal ZIP code for Trinidad is 95570.  This postal ZIP code extends out into the surrounding rural, unincorporated neighborhoods.  In the 2000 Census (3), 2,352 people lived within the 95570 ZIP code area; therefore some two thousand of them lived in the unincorporated areas beyond the City Limits.  South of town within the ZIP code are the rural neighborhoods of Westhaven and Moonstone with 1,044 residents in the 2000 Census (1), down from 1109 in the 1990 Census (4).  North of town within the ZIP code area are many smaller rural neighborhoods with a total of 997 residents in the 2000 Census.

References

(1)  Population Totals for Census Designated Places (CDPs) in Humboldt County, California, 2000 (Humboldt County Planning Department)

(2)  1990 U.S. Census Gazeteer Query for Trinidad, California

(3)  2000 U.S. Census Zip Code Tabulation Areas (ZCTAs) [5MB text file]

(4)  1990 U.S. Census Gazeteer Query for Westhaven-Moonstone, California