John B. Crowell Jr., one of the Reagan administration's more controversial Cabinet-level appointees, won easy confirmation as overseer of the national forests yesterday as the Senate brushed aside unanswered questions about his past service as a lawyer for a major timbering company.

A solid Republican front picked up 19 Democratic votes to approve Crowell as assistant secretary of agriculture for natural resources and environment. The roll-call was 72 to 25; all 25 were Democrats.

The 25 votes against Crowell were the most yet cast against any Reagan nominee. The previous record-holder was William P. Clark, who had 25 opponents to his nomination as deputy secretary of state.

In his new job, the former general counsel for the Louisiana-Pacific Corp., the major purchaser of timber from the national forests, will run the U.S. Forest Service.

The battle over Crowell's nomination had less to do with his philosophy -- he has been a caustic critic of past federal timbering policies -- than with questions about his involvement in a bid-rigging and collusion case in an Alaska national forest.

During two days of debate, Sens. Patrick J. Leahy (D-Vt.) and Edward M. Kennedy (D-Mass.) contended that Crowell had knowledge of and involvement with a Louisiana-Pacific subsidiary, the Ketchikan Pulp Co., found guilty by a federal judge of antitrust practices.

Crowell argued throughout weeks of controversy that he had no knowledge of Ketchikan's activities. Leahy and Kennedy charged that company memoranda proved otherwise, or at least raised enough doubt that he should be questioned anew by the Senate Agriculture Committee.

Crowell's chief defender, Agriculture Chairman Jesse Helms (R-N.C.), acused the critics of using ""specious, veiled innuendos . . . to imply that Mr. Crowell is less than a worthy American."

Helms said Crowell's record "remains unblemished," despite a Kennedy asertion that the memos showed clear involvement of the nominee in the illegal activities.

The Sagebrush Rebellion took legislative from yesterday as about 50 members of Congress sponsored a bill that could turn over 460 million acres of land to 12 western states.

While the older eastern states retained ownership of their land when they joined the Union, large portions of the states from the Rocky Mountains west to the Pacific Coast have remained in federal ownership -- an average of 63 percent and climbing to 87 percent in Nevada. The western states have been mounting a cry that the federal lands within their borders -- except national parks, forests, and Indian reservations -- should belong to them.

Environmentalists have protested that the states want the land so they can turn it over to developers to exploit without restraints. Sen. Orrin Hatch (R-Utah), a principal sponsor of the bill, said the measure contains safeguards against rape of the land. States could obtain title to the land only if found capable of managing it and could sell land only by complying with standards for federal land sales. Hatch said he and his co-sponsors expect a fight over the legislation that could go on for years.