Iodine supplements usually aren't necessary if you live in the United States or in most developed countries. Some alternative medicine practitioners recommend iodine tablets or kelp supplements â which are high in iodine â for people with hypothyroidism.
The area within the entire watershed of the Rio Grande is some 336,000 square miles (870,000 square km). Because a large proportion of the riverâs basin is arid or semiarid, however, only about half of the total area, or about 176,000 square miles (456,000 square km), actually contributes to the riverâs flow.
The total length of the Colorado River is 1,450 miles. Within the Grand Canyon, it measures 277 miles from Lees Ferry in the east to Grand Wash Cliffs, near Lake Mead in Nevada. Speaking of the Colorado River, its average width in the Grand Canyon is 300 feet. It's narrowest width is 76 feet.