Dolly spawned thunderstorms as far away as Houston, 400 miles up the coast. Tornado watches were in effect for many coastal counties between Corpus Christi and Houston.
In Mexico, a 102-year-old woman and seven family members fled their wooden shack in the fishing community of Higuerilla and spent the night at a shelter in Matamoros.
"I don't know if my poor house will withstand the rain and wind," Maria Miguel said.

A man and his son look out over the womens section at a shelter for hurricane evacuees in Matamoros July 23, 2008. Hurricane Dolly strengthened on Wednesday as it neared southern Texas, and was expected to lash low-lying areas on the US-Mexico border with winds of 100 mph (160 kph) and torrential rain when it comes ashore around mid-day. [Agencies] |
Many of those who headed north to escape the storm were stopped at inland Border Patrol checkpoints, where agents opened extra lanes so they could check documentation. At one checkpoint on Interstate 77, smugglers were caught with 5,000 to 8,000 pounds of marijuana.
Power was knocked out to more than 56,200 customers in three border counties. South Padre Island also lost power.
Thousands of people fled to shelters in towns on both sides of the border while police and National Guard troops patrolled neighborhoods.
In Brownsville, the wind bent over palm trees and tossed debris across the all-but empty streets. The windows and doors of shops were boarded up with plywood, and most businesses were closed.
The US Census Bureau said that based on Dolly's projected path, about 1.5 million Texans could feel the storm's effects. Gov. Rick Perry declared 14 south Texas counties disaster areas and sought federal disaster declarations.
As Dolly approached, oil and gas companies in the Gulf of Mexico evacuated workers from 62 production platforms and eight rigs, according to the US Minerals Management Service, which monitors offshore activity.
Shell Oil, which didn't expect production to be affected by the evacuations, also secured wells and shut down operations in the Rio Grande Valley, where it primarily deals in natural gas.
The last hurricane to hit the US was the fast-forming Humberto, which came ashore in South Texas last September. Dolly is the 26th hurricane to make landfall in the US in July since record keeping started in 1851, according to federal researchers.
The busiest part of the Atlantic hurricane season is usually in August and September. So far this year, there have been four named storms, two of which became hurricanes. Federal forecasters predict a total of 12 to 16 named storms and six to nine hurricanes this season.