Bsrgvty

Once the colonial era began around 1500 or 1600, Europeans and Native Americans started trading. As far as I'm aware, the principal trade was beaver pelts in exchange for iron axes.

But I'm interested in trade amongst the Native Americans themselves, before the colonial era. Did any trade go on? If so, what was it? It seems like each tribe could make whatever it wanted from the materials nearby, so I am very interested in the trade situation or lack thereof.

Note, I'm also aware of some Icelanders coming to Canada around the year 1000. Not really interested in that either, as far as this question is concerned. Only care about tribe-to-tribe trade of Native Americans.

Flint points, obsidian, buffalo hides, salt, pearls, shells and (as mentioned by T.E.D.) copper were among item traded by Native Americans before Europeans arrived. That said, trade in North America prior to European contact varied greatly in its extent and volume, depending on area and epoch.

From Trade Among Tribes: Commerce on the Plains before Europeans Arrived by Samuel Western (Wyoming State Historical Society), our two main sources of this trade come from archaeology and from accounts of the first European traders to reach various regions.

From archaeology,

Indians of the southern and northern Plains traded with each other for
thousands of years. Flint points 13,000 years old, chiseled from the
Texas quarries, have been found in eastern New Mexico. Quarried stone
from the Obsidian Cliffs near Mammoth Hot Springs, Wyo. in Yellowstone
Park, traveled to the the Ohio River Valley around 100-350 CE.

.....

Archeological artifacts do suggest...that native-to-native trade
expanded over time. Emory Dean Keoke and Kay Marie Porterfield,
authors of the Encyclopedia of American Indian Contributions to the
World, say that the Hohokam tribe, centered in present day Arizona,
traded seashells, which they had acquired from the Mojave tribe, for
buffalo hides from various southern Plains tribes. “By between 500 and
200 B.C., North American Indians had established a vital network of
trade.”

Also,

A research team including Matthew Sanger, assistant professor of
anthropology at Binghamton University, State University at New York,
has found a copper band that indicates ancient Native Americans
engaged in extensive trade networks spanning far greater distances
than what has been previously thought.

The researchers found that the band was made from copper that

originated in the Great Lakes region, more than 1,500 km away. Copper
sources each have their own unique chemical makeup, including very
small amounts of trace elements. As such, archaeologists can match
manufactured objects to their sources by comparing their chemical
signatures,...

Copper was also traded in the Southeast (among other regions), along with salt, pearls and probably ceramics. Many kinds of stones / minerals (sandstone, soapstone, chert, galena etc.) were also traded, both before and after their transformation into status items and / or weapons.

On food (other than corn / maize), the sources are less definite. On the one hand,

Because North America lacked an animal that could be domesticated for
draft purposes and was wanting for any other efficient means of
regional and continental transportation as well as an organized market
system, the people of this continent did not trade food products to
any great extent.

Source: 'Chapter 1' in Jonathan E. Ericson & Timothy G. Baugh (eds), 'Prehistoric Exchange Systems in North America'

On the other hand, it is impossible to rule out local exchange of foodstuff. Michael B. Stewart, in Late Archaic through Late Woodland Exchange in the
Middle Atlantic Region (in Ericson & Baugh) states:

Foodstuffs and artifacts fashioned from organic materials are poorly
preserved in the archaeological record of the region, their absence
serving to remind us that we are seeing only a part of the whole
picture of Native American material culture.

Nonetheless, Susan C. Vehnik and Timothy G. Baugh in Prehistoric Plains Trade (in Ericson & Baugh) cite Henning (1983a) as suggesting that there was some trade in bison hides and dried meat in the period 800 to 1200 AD, while trade in 'bison products' is mentioned in relation to the Southwestern Pueblo in the period up to 1650. Given that Native Americans could and did hunt bison before they had horses, the trade in items derived from these hunts is at least plausible.

Accounts of early European traders are also a valuable source of information as

artists who visited the upper Missouri and Rocky Mountains in the
1830s noticed tribes hanging onto traditions or only selectively using
European goods.

The addition of European goods did not suddenly change Native American trading habits, although it should also be pointed out that tribes sometimes acquired European goods from other tribes (i.e. without meeting Europeans themselves). Tribes

tapped Wyoming’s abundant natural resources for desired trade goods:
quartzite or obsidian for knives, scrapers and arrowheads; buffalo for
robes, dried meat, pemmican and hides; soapstone for bowls; elk or
deer for tanned hides; and horn, particularly from the bighorn sheep,
for making bows, which were highly desired.

"Trade links among northern Plains tribes about 1775, before the arrival of Europeans. Courtesy W. Raymond Wood." Source: WyoHistory.org

Western notes that:

The Shoshone, it seems, traded with everyone, including northwest and
southwest tribes. Other Rocky Mountain and central Plains tribes also
took goods to the Missouri River valley to trade for corn, pumpkin,
squash and native-grown tobacco (Nicotiana quadrivalvis, Pursh)...

Over time, European goods were traded alongside / in exchange for local products:

Corn also appealed to former woodland tribes. “For the Sioux, corn was
more important than blood,” says James P. Ronda, professor of Western
American History at the University of Tulsa. In August, “as in every
other late summer and early fall, Sioux bands flocked to the Arikara
towns, bringing meat, fat, and hides from the plains and
European-manufactured goods from the Dakota Rendezvous.”

An area which may require a closer look is the southwestern cultures. Trade routes were actually quite well established in these regions, with many items being traded. An article Indigenous Trade: The Southwest , lists many of these trade materials(emphasis highlighting trade materials mine):

Anasazi. Around the end of the first millennium a.d., Anasazi Indians living in
the Southwest had become fully integrated into the pansouthwest trade
network. They supplied highly valued turquoise and, to a lesser
extent, obsidian to tribes located along the Gulf of California in
exchange for luxury goods such as bracelets and pendants fashioned
from Pacific shells. They also traded turquoise with Mesoamerican
civilizations such as the Toltec Empire for high-prestige items such
as macaw feathers, ornaments, and pottery. This intercourse had
important consequences because it helped spread Mesoamerican pottery
styles, religious customs, crops, and agricultural techniques to North
America.

The next section discusses a later time, and repeats some of the information included in Lars answer concerning the trade between the Pueblo and Plains cultures, but I'll again include it to highlight the materials being traded.

New Avenues. After the pansouthwest commercial system collapsed
between 1200 and 1400, the pueblo-dwelling Indians of the Rio Grande
valley began to trade with semisedentary plains tribes such as the
Apache. Pueblo tribes such as the Tewas exchanged surplus corn, cotton
textiles, ceramics, and turquoise for the Plains Indians’ tallow,
salt, buffalo meat, and hides. This new commercial intercourse was
based, in part, on the same system of reciprocal gift giving that
governed trade among the Indians of eastern North America. Commerce
between Pueblo and Plains tribes was substantially more complex than
reciprocity-based trade, however, because it involved the
complementary exchange of surplus goods. It thus allowed the Plains
tribes and, to a greater extent, the Pueblo Indians to shift from a
simple, subsistence-based economic system to a more complicated one
based on specialized production.

By some accounts, oils and furs were traded in the Pacific Northwest.

Early accounts stress the enormous importance
of oils in trade, feasting, and food. The Makah used to compete to see who could
drink the most whale oil at feasts (Colson 1953). People were desperate for oils. Suffice it to say that “ooligan” is derived
from a Tsimshian word meaning “savior,” now used for Jesus. Watertight boxes of oil from the ooligan
(oolichan, eulachon), a smelt that is mostly fat by dry weight, were traded all
up and down the coast. The Haida sailed
their great canoes over tens of miles of some of the most dangerous waters in
the world, and traded their most valuable possessions, to get these boxes of
oil. Northwest Coast: Traditional Indigenous Relationships with Plants and Animals

Non-residents of the Nass (i.e. Non-Nishga cultures) journeyed from the interior early in the year, while the snow was still deep in order to reach the Nass River for fishing time (mid March). They traveled hundreds of miles with their belongings on sleighs drawn by dogs or themselves. The non-Tsimshian among them also brought furs (usually marmot and rabbit skins, but also martin, mink, and bear skins), to pay the resident cultures of the river for fishing rights and to pay them for using their nets and shelter in their fishing lodges.

In regions of Coastal British Columbia where there were no eulachon, the people obtained them through trade, usually in the form of eulachon oil [62]. Eulachon oil was so highly prized by many cultures that the Northwest Coast cultures traded it long distances eastward to cultures in the interior along so-called “grease trails”. There are several ancient trade routes to the coast called “grease trails” and the great explorer Alexander Mackenzie made his famous journey to the Pacific ocean following one such “grease trail” [5]. The First Nations of the Northwest Coast traveled the grease trail into the interior to trade the oil with the Athapaskan-speaking tribes and they traded the oil by canoes to the south and north 1. The Gitksan Tsimshian, who had a winter village on a grease trail to the Nass, traded soapberries, dried fish, meat and tanned hides to the Niska of the Nass for eulachon [30, 58].

Eulachon