Identifying Large Tamarisk (Salt Cedar) Along the Colorado River

The tree you describe—large trunks growing almost horizontally, multiple trunks ~2 feet thick, light green, flat, evergreen-like foliage along the Colorado River south of Blythe, California—is almost certainly a mature tamarisk (salt cedar), Tamarix spp.

While often described as a shrub 8–10 feet tall, tamarisk can reach 20+ feet and develop thick, gnarled trunks with age, especially in riparian areas with fluctuating water tables. It tolerates both prolonged flooding and extreme drought, making it dominant along regulated rivers like the Colorado.

Confirmation steps:

• Compare foliage: tamarisk leaves are tiny, scale-like, and bluish-green, clasping the stem.
• Break a twig: it should be flexible, not snap crisply.
• Look for pinkish-white flower plumes in spring/summer.
• Consult a local extension office or riparian ecologist—they can verify with a sample.

If it's tamarisk, be aware it's considered invasive in many Western U.S. waterways, outcompeting native willows and cottonwoods.