Register for free at https://npspermits.us/grandcanyon/river/login.cfm
Once registered you can submit an online lottery application for $25.

Mailing Address for US Postal Service:
River Permits Office
Grand Canyon National Park
Box 129
Grand Canyon, AZ 86023

Mailing Address for Other Carriers:
River Permits Office
Ranger Ops., #1 Center Road
Grand Canyon, AZ 86023

Phone (928) 638-7843
Fax (928) 638-7844
Automated (800) 959-9164 Grand Canyon River Trip Information Center

For the on-line lottery registration and application:
http://www.nps.gov/grca/planyourvisit/weightedlottery.htm

And here are the regulations for noncommercial trips:
Grand Canyon National Park Regulations for Noncommercial River Trips (PDF)

COLORADO RIVER GC, FOLLOW UP LOTTERY DATES

Available launch dates can be found at http://www.nps.gov/grca/planyourvisit/cancelled-dates.htm

OTHER RIVERS THAT CEIBA RENTAL EQUIPMENT IS AVAILABLE FOR:

Colorado River - Westwater Canyon
Westwater River Permits
Bureau of Land Management
Grand Resource Area
82 E. Dogwood #G
Moab, UT 84532-2968
(435)259-7012 8 am-12 noon
http://www.blm.gov/ut/st/en/fo/moab/recreation/river_recreation/
westwater_canyon.html

Green & Yampa, Canyon of Lodore
River Office
Dinosaur National Monument
4545 Hwy. 40
Dinosaur, CO 81610
(970) 374-2468
http://www.nps.gov/dino/planyourvisit/privateriverrafting.htm

Green River - Desolation Canyon
Bureau of Land Management
Price Field Office
125 South 600 West
Price, UT 84501
(435) 636-3622 Calls accepted 8 A.M. until 12 noon Mountain Time, Mon-Fri.
http://www.blm.gov/ut/st/en/fo/price/recreation/riverinf.html
Flows: Green at Green River

Salt River - Upper
River Permits and Info
Tonto National Forest
2324 E. McDowell Rd.
Phoenix, AZ 85006
(602) 225-5200
(928) 402-6200 for cancellations

Tonto National Forest for information and permits:
http://www.fs.fed.us/r3/tonto/recreation/rec-permits-srpermits.shtml

San Juan River
River Permits and Info
San Juan Field Office
PO Box 7
Monticello, UT 84535
(435) 587-1544
(435) 587-1504 Leave a message to receive a permit application.
(425) 587-1518 Fax
http://www.blm.gov/ut/st/en/fo/monticello/recreation/permits/san_juan_river.html

Cataract Canyon
2282 South Resource Blvd.
Moab, UT 84532-8000
(435) 259-4351 Phone
(435) 259-4351 Fax
Email for questions: canres@nps.gov
Permit: required, applications accepted starting January 1
Fee: $30
Web: http://www.canyonlands.national-park.com/visit.htm#raft - permit


Dolores River
Information: (970) 565-7562
Information: (970) 385-1354
Flow Predictions: Dolores Water Conservancy District (970) 565-7562
or http://www.doloreswater.com/
Current flow: BOR (800) 276-4828
Or call BLM (970) 385-1354 or visit their web page for links to flows.

Bradfield to Slickrock to Bedrock
Bureau of Land Management
Dolores Field Office
100 N. 6th Street
PO Box 210
Dolores, CO 81323
http://www.co.blm.gov/sjra/sjdolores.htm
(970) 882-7296
(970) 882-6817 Rick Ryan is River Ranger for all sections in Colorado.

Bedrock to Gateway
Uncompahgre Field Office
2505 South Townsend
Montrose, CO 81401
(970) 420-5300

Gateway to Dewey Bridge
Bureau of Land Management
Grand Resource Area
82 East Dogwood
Moab, Utah 84532
(435) 259-7012 8AM-12PM Mon-Fri.