South of Alamosa, a 74-mile segment of the Rio Grande is one of the country’s eight original rivers to be protected under the National Wild and Scenic River Act. The designated portion flows through the 800-foot-deep Rio Grande Gorge, which abounds with cutthroat trout, in the Rio Grande del Norte National Monument. WSR protection has allowed the belly of the Rio Grande’s 1,900-mile stretch to remain as wild as it was 50 years ago.

The best time of year to get on the Rio Grande is mid-June to October. The salmon fly hatch typically occurs mid- to late June. Although the hatch may occur during runoff, the water is clear enough to permit dry-fly fishing.

During the summer months you can more easily take advantage of the massive caddis fly hatches that allow the local trout to grow to such a large size. As with all rivers in Colorado you can fish year round, but the best season for fly fishing is definitely that mid-June to October window.

Mid morning to late afternoon offers the best wade fishing, and if you decide to float the lower reaches near South Fork you can fish all day and still land some excellent catches.

Brown trout swim the Rio Grande in incredible numbers, and fish are found everywhere. Browns are particularly fond of holding in deeper water near the banks and under the roots of willows in slow-moving water. In choppy runs about a foot deep trout will hold in the rocks on the bottom, freely rising to dry flies or taking nymphs at any depth. Look for current seams where a slow current passes against a faster one. Good fish can be taken from lies within a rod’s length from where you are standing. Be watchful for hidden deep runs where large nymphs can snare a good-sized brown.

The Rio Grande flows from the San Juan Mountains, then turns to head south in Alamosa. The South Fork officially begins at Wolf Creek Pass, famous for its powder skiing. From here, the river parallels Highway 160, so public access is relatively easy; there are also several US Forest Service campgrounds along the river for this stretch, and much of the Rio Grande is wadeable here.

The river gets bigger between South Fork and Del Norte, and thanks to lack of public access between the two towns, float fishing is a popular choice, though the fishing easement partway between the two towns is occasionally wadeable. If you don’t have an oar-boat (or a friend you can bribe), consider hiring a local guide, who can take you downriver and show you the best spots to fish, along with the perfect flies to use during the time of year you’re there.

The section between South Fork and Del Norte is designated Gold Medal Water, and it’s not hard to see why. Big brown and rainbow trout can’t wait to latch onto flies ranging in size from midges to grasshoppers. Here, you’ll probably want to use a dropper and a dry fly, since the river is considerably deeper than it is upstream. Browns here tend to hold in deeper water near the banks and under willow roots, and are known for not being fussy.

The Rio Grande, known in Mexico as the Río Bravo del Norte or simply the Río Bravo, is one of the principal rivers in the southwestern United States and in northern Mexico. The length of the Rio Grande is 1,896 miles. It originates in south-central Colorado, in the United States, and flows to the Gulf of Mexico.

Rio Grande, Spanish Río Grande del Norte, or (in Mexico) Río Bravo, or Río Bravo del Norte, fifth longest river of North America, and the 20th longest in the world, flows through the state of New Mexico then forming the border between the U.S. state of Texas and Mexico. Rising as a clear, snow-fed mountain stream more than 12,000 feet above sea level in the Colorado Rocky Mountains, the Rio Grande descends across steppes and deserts, watering rich agricultural regions as it flows on its way to the Gulf of Mexico at Brownsville, Texas. The total length of the river is about 1,900 miles.

On July 8, 1694, Spanish Conquistador Don Diego de Vargas and his army, two weeks before the Battle of Astialakwa, reached Costilla County. Diego Vargas is not the first Spaniard in Colorado. Juan de Archuleta led an expedition into Colorado in 1664 – but his expedition is the first traceable Spanish expedition into Colorado. In 1647, Governor Luis Rosas fought with the Utes in northern New Mexico. While Rosa came near Colorado, it has not been verified he actually did.

Costilla County was the first area of Colorado to be settled by European-Americans. The county made up the major part of the Sangre de Cristo Land Grant awarded by the government of New Mexico to the Carlos Beaubien family in 1843. Hispanic settlers from Taos, New Mexico, officially established San Luis on April 9, 1851. Costilla County was one of the original 17 counties created by the Territory of Colorado on November 1, 1861. The county was named for Costilla Creek. Although San Miguel was originally designated the county seat, the county government was moved to San Luis in 1863.

Antonito began life as a sheep herding camp known as San Antonio Junction, referring to its proximity to the Conejos and San Antonio rivers. When the Denver & Rio Grande Railroad built its line south from Alamosa, the town was renamed Antonito and became an important town on the railroad line. The town was incorporated in 1889. There are currently no major industries located in Antonito, but the historic Cumbres & Toltec Scenic Railroad has one terminus in Antonito and the other in Chama, New Mexico. The C&TS also has maintenance facilities and rail yard in the town.