It is known that a large body of Mormon emigrants are en route to California for the purpose of settling in that country.  You are desired to use all proper means to have a good understanding with them, to the end that the United States may have their co-operation in taking possession of and holding that country.  It has been suggested here that many of these Mormons would willingly enter into the service of the United States and aid us in our expedition against California.  You are hereby authorized to muster into service such as can be induced to volunteer; not, however, to a number exceeding one-third of your entire force.  Should they enter the service they will be paid as other volunteers, and you can allow them to designate, so far as it can be properly done, the persons to act as officers thereof.  It is understood that a considerable number of American citizens are now settled on the Sacramento river, near Sutter’s establishment, called “Nueva Helvetia,” who are well disposed toward the United States.  Should you, on your arrival in the country, find this to be the true state of things there, you are authorized to organize and receive into the service of the United States such portion of these citizens as you may think useful to aid you to hold the possession of the country.  You will in that case allow them, so far as you shall judge proper, to select their own officers.  A large discretionary power is invested in you in regard to these matters, as well as to all others, in relation to the expedition confided to your command.

The choice of routes by which you will enter California will be left to your better knowledge and ampler means of getting accurate information.  We are assured that a southern route (called the Caravan route, by which the wild horses are brought from that country into New Mexico) is practicable, and it is suggested as not improbable that it can be passed over in the winter months, or at least late in autumn.  It is hoped that this information may prove to be correct.

In regard to routes; the practicability of procuring needful supplies for men and animals, and transporting baggage is a point to be well considered.  Should the president be disappointed in his cherished hope that you will be able to reach the interior of Upper California before winter, you are then desired to make the best arrangement you can for sustaining your forces during the winter, and for an early movement in the spring.  Though it is very desirable that the expedition should reach California this season (and the president does not doubt you will make every possible effort to accomplish this object), yet if, in your judgment, it cannot be undertaken with a reasonable assurance of success, you will defer it, as above suggested, until spring.  You are left unembarrassed by any specific directions in the matter.

It is expected that the naval forces of the United States which are now, or will soon be in the Pacific, will be in possession of all the towns on the seacoast, and will co-operate with you in the conquest of California.  Arms, ordnance, munitions of war, and provisions to be used in that country, will be sent by sea to our squadron in the Pacific for the use of the land forces.