This site gives a good comparison of parts per million, as well as conversions.

An educational portal that consolidates all kinds of useful information about volcanoes. Choose from a menu of topic options and start exploring or use the site's search tool to find just what you're looking for.

Offers key information regarding Oregon history, famous people, cities, geography, state parks, tourism, and historic sites. A fact sheet of information and a quiz are also available.

Highlights four Supreme Court cases that dealt with the balance of federal and state power. In each case the majority opinion is given but might not be what is expected.

In this unit, students learn how the United States began to grow as soon as it became a nation, and they examine the effect of this growth on societies already established in North America. Register for a free account to download teacher...

This passionate essay provides an informative history of the battles between Northwest Indians and the US in the 1960s over fishing rights and broken treaties.

Lewis and Clark National Historic Trail is approximately 4,900 miles long, extending from Pittsburgh, Pennsylvania, to the mouth of the Columbia River, near present day Astoria, Oregon. It connects 16 states. Today, visitors can follow...

Interactive and animated maps and timelines of historical events and time periods in American history from pre-European times until post-World War II.

Primary source information about traveling the Overland Trails, both to Oregon Country and California.

Describes the significant territorial changes that took place in the United States under the presidency of James K. Polk. These included the annexation of Texas, the settling of the dispute with Great Britain over claims to Oregon...

An image of the Oregon State Capital.

This clickable map of the United States gives students access to research information from history and tourism to attractions and famous historic figures.

An image of the Oregon State Flower.

A map of the Oregon Territory between the time of exploration by George Vancouver (1792) and the Oregon Treaty of 1846. The map is color-coded to show the disputed claims of the British and United States, the Russian American line of...

An image of the Oregon State Bird.

An image of the Oregon State Animal.

An image of the Oregon State Animal.

An image of the Oregon State Capital.

An image of the Oregon State Capital.

An image of the Oregon State Capital.

An image of the Oregon State Fish.

An image of the Oregon State Tree.

A map of the Oregon Country showing the adjustments to the boundaries between 1818-1846, including the boundary established in 1818 to the east of the jointly controlled territory (Great Britain and the United States), the southern...

A map of the Oregon Territory showing the boundary on the 49th Parallel established by treaty between Great Britain and the United States in 1846, dividing what was once jointly held territory. The map also shows the boundary with Upper...