168 : FORT YUMA 
the tidal wave at its mouth, which has been noticed 
by all who have attempted to ascend it; and although 
the United States has been in possession of California 
six years, no official survey, exploration, or reconnois- 
sance has yet been made of tlie head of the gulf, or of 
the river below the Gila. The want of this is my 
apology for giving some notices of the entrance of 
this river by its discoverer and subsequent explorers. * 
As early as the year 1540, Fernando Alarchon, in 
a voyage to explore the Gulf of California, by order of 
Antonio de Mendoca, Viceroy of New Spain, disco- 
vered the mouth of the Colorado. It appears that 
‘‘the pilots and the rest of the company” made serious 
objections to entering the river, and proposed that the 
fleet should return. “But,” says the persevering navi- 
gator, in his letter to Mendoga, ‘ because your Lord- 
ship commanded me, that I should bring you the 
secret of the gulf, I resolved that, although I had 
known I should have lost the ships, I would not have 
ceased for any thing to have seen fhe head thereof: 
and therefore 1 commanded Nicolas Zamorano, pilot 
major, and Dominico del Castello, that each of them 
should take a boat, and their lead in their hands, and 
run in among these shoals, to see if they could find out 
* I should do injustice to Major Heintzelman not to notice his _ 
efforts to explore the Colorado below Fort Yuma. He was unprepared 
with instruments for an accurate survey ; yet he did make a reconnols 
sance to ascertain the feasibility of getting his supplies up, which enabled 
him to lay down approximately the course of the river. I am indebted 
to him for a copy of this map, which is now in the hands of the engr 
neers of the Commission, and is all the material they possess for making 
a map of this portion of the country. 
