Fort Robidoux, a fur trading post also known as Fort Uintah and Fort Winty, was located at the junction of the Uintah and Whiterocks rivers in the Uinta Basin of northeastern Utah.
 It was founded in 1832 after Antoine Robidoux bought out the Reed Trading Post that had been in operation at that site since 1828.
 Robidoux had traded for beaver pelts in the Uintah Basin region as early as 1824.
 By 1828 he had established his first trading post in the intermountain corridor of the western slopes of the Rocky Mountains on the Gunnision River near present-day Delta, Colorado.
 Robidoux took out Mexican citizenship and married Carmel Benevedes, the adopted daughter of the governor of New Mexico, that same year.
 This enabled him to obtain a Mexican trading and trapping license.
Jüterbog Airfield (also known as Altes Lager airfield) is an abandoned military air base located west of the town of Jüterbog, in Brandenburg, Germany.
 Nowadays paragliders and hang gliders start from Altes Lager.
Fort Alexander -"Sagkeeng" Ojibway (mouth of the river) is a community in Manitoba, Canada, located on the Sagkeeng First Nation, on the south bank of the Winnipeg River.
 The Sagkeeng area, or the mouth of the Winnipeg River, was originally settled with native camps used for fishing, hunting, and trade.
 During the fur trade era, La Vérendrye built a trading post, named Fort Maurepas, on the north side of the river; this post was abandoned near the end of the French period.
 In the year 1792, a clerk for the North West Company, Toussaint Lesieur, built a post on the south side, which became an important provisioning post for the canoe brigades.
 Bags of pemmican, brought from the North West Company's posts on the upper Assiniboine, were stored here and taken as needed by the canoe brigades passing between Grand Portage (later, Fort William) and the far northwest.
 This post was usually referred to as Fort Bas de la Rivière, because of its location at the bottom of Winnipeg River, and it seems to have functioned as the capital of the Company's Lake Winnipeg district.
 The Hudson's Bay Company operated its own post here for a few years between 1795 and 1801.
 In 1807, the North West Company partner Alexander MacKay rebuilt the post on a nearby site.
 Beginning in 1808, the new post was known as Fort Alexander.
 After the Northwest and Hudson's Bay Companies merged in 1821, Fort Alexander was operated as a trading post for the natives in the region.
The Dutch Slave Coast (Dutch: "Slavenkust") refers to the trading posts of the Dutch West India Company on the Slave Coast, which lie in contemporary Ghana, Benin, Togo and Nigeria.
 The primary purpose of the trading post was to supply slaves for the plantation colonies in the Americas.
 Dutch involvement on the Slave Coast started with the establishment of a trading post in Offra in 1660.
 Later, trade shifted to Ouidah, where the English and French also had a trading post.
 Political unrest caused the Dutch to abandon their trading post at Ouidah in 1725, now moving to Jaquim, at which place they built Fort Zeelandia.
 By 1760, the Dutch had abandoned their last trading post in the region.
The Viking Age is the period from the late 8th century to the mid-11th century in European history, especially Northern European and Scandinavian history, following the Germanic Iron Age.
 It is the period of history when Scandinavian Norsemen explored Europe by its seas and rivers for trade, raids, colonisation and conquest.
 In this period, the Norsemen settled in Norse Greenland, Newfoundland, and present-day Faroe Islands, Iceland, Norway, Scotland, England, Ireland, the Netherlands, Germany, Ukraine, Russia, and Turkey.
Altes Lager (German for "Old Camp") is a site 1.5 km south of the village of Menzlin near Anklam, Western Pomerania, Germany.
 The site, on the banks of the river Peene, was an important Viking trading-post during the Viking Age.
 At that time, Pomerania was inhabited by Slavic Wends, yet several Viking trading-posts were set up along the coast (the nearest were Ralswiek to the West and Jomsborg/Wollin to the east).
Kræmmerholmen is an old trading post on the island of Fedje.
 The trading post is now in the village of Fedje which is the main village on the island of Fedje in the municipality of Fedje, Hordaland county, Norway.
 The main building of Kræmmerholmen was moved to this location in about 1652.
 During the 18th century, Fedje was an important trading place, with the small island Kræmmerholmen being the location where the trading took place.
 In 1702, merchants who were citizens of Bergen were granted permission to set up a trader's inshore channel.
 Trade was managed by a merchant's ablest foreman.
 Christopher Kahrs, one of the richest merchants in Bergen, purchased Kræmmerholmen in 1799.
 In addition to the actual trading post, he also owned all of the island of Fedje, including tenant farms and all the dwelling houses.
Bowlin's Old Crater Trading Post is a former trading post which was located along historic U.S. Route 66 in Bluewater, New Mexico.
 The trading post was built in 1954 by Claude Bowlin.
 Bowlin had traded with local Navajo since 1912, and he built his first trading post at the site in 1936.
 The store's name came from a volcanic crater that drew tourists to the area.
 While the trading post initially served the Navajo, it soon served tourists as well due to increased traffic on Route 66.
 Inspired by his success, Bowlin built a chain of stores throughout New Mexico, which became Bowlin Travel Centers, Inc. In 1954, Bowlin replaced his original trading post with the current building.
The Aptucxet Trading Post Museum is a small open-air historical museum in Bourne, Massachusetts.
 The museum's main attraction is a replica of the 17th-century Aptucxet Trading Post, which was built by the Pilgrims of Plymouth Colony in order to trade with the Wampanoags and the Dutch.
 In addition to the trading post, the museum also features a replica of a 19th-century saltworks, the relocated 19th-century Gray Gables Railroad Station, and a wooden smock windmill.
The Jack Rabbit Trading Post is a convenience store and curio shop located on former U.S. Route 66, five miles west of Joseph City, Arizona city limits off of Exit 269 on Interstate 40.
 The trading post hails from Route 66's glory days, and is currently in operation.
 With a large fiberglass jackrabbit that can be mounted (for pictures), the facility is considered a major Route 66 attraction by enthusiasts.
 It was famous for numerous billboards up and down US 66 (and in some other locations) which had the silhouette of a jackrabbit and the distance from that sign to the trading post.
 In front of the store was another such billboard with "HERE IT IS" written underneath it.
 Jack Rabbit is owned by the Jaquez family.

Question: During which period was Altes Lager an important Viking trading post?
Answer: the late 8th century to the mid-11th century